research contract: noise mapping industrial sources

For the benefit of business and people

Acoustic Technology

Department for Environment, Food & Rural Affairs

Research Contract – Noise Mapping Industrial Sources

Final Report

Technical Report No: AT 5414/2 Rev 1

FINAL REPORT ON DEFRA RESEARCH PROJECT NOISE MAPPING INDUSTRIAL SOURCES TECHNICAL REPORT NO: AT 5414/2 REV 1

TECHNICAL REPORT NO: AT 5414/2 REV 1 DATE: 13TH OCTOBER 2003

SUBMITTED TO: DEFRA ZONE 4/G17

ASHDOWN HOUSE 123 VICTORIA STREET LONDON SW1 6DE

ATTENTION: MR JOHN STEALEY SUBMITTED BY: BUREAU VERITAS ACOUSTIC TECHNOLOGY 36-38 THE AVENUE SOUTHAMPTON

SO17 1XN PREPARED BY:

S J STEPHENSON SENIOR CONSULTING ENGINEER B C POSTLETHWAITE PRINCIPAL CONSULTANT

APPROVED BY: B R WOOD PRINCIPAL CONSULTANT

PROJECT QUALITY ASSURANCE This Project has been undertaken in accordance with both the Group and local Quality Management System specifics registered by BSIQA to ISO 9001. (Certificate No. FS34143 in the name of Bureau Veritas Group , of which Bureau Veritas Acoustic Technology forms part of the UK organisation).

SUMMARY

The Department for Environment Food and Rural Affairs, Defra, has commissioned Bureau Veritas Acoustic

Technology (BVAT) to undertake a research project to investigate the acoustic modelling of noise from

industrial sources to assist in its noise mapping processes.

The development of a standardised approach on how to map sources of industrial noise is critical to mapping

the ambient noise climate in England as the UK has no national standard. A simple methodology, which

allows consistent and reasonably accurate representation of industrial noise sources for noise mapping, will

provide the necessary firm basis for assessing the effects of industrial noise and mitigation where this is

considered necessary.

A methodology for representing industrial sources in a noise model which is simple, reproducible and robust

has therefore been developed. Provision has been made within the study to allow different sizes and

complexities of industrial development to be modelled.

As part of the project, BVAT has investigated the formats of some national databases and population density

databases and reviewed the impact this will have on the methodology to represent industrial noise sources.

The project also researched the feasibility of using non-acoustic means to assign noise levels to sources of

industrial noise. A review was conducted to establish the types of information routinely gathered by different

industries and its accessibility and confidentiality. In addition, a review of work carried out in other European

countries in this field was carried out. At present, it is not considered a viable proposition, in England, to use

non-acoustic means to determine noise source strengths. It is, however, possible that such a method might

be developed in due time in the light of more extensive experience.

It was therefore considered necessary to use measurements to assign noise levels to sources of industrial

noise. The most appropriate method of measurement for different types of sources has been investigated and

clearly specified. The results illustrate that source determination can be carried out utilising both close-

proximity (i.e. site boundary) and distant measurements. However, a correction for ground effects is

necessary when using distant measurements over soft ground. The preferred measurement method depends

upon access to measurement locations as well as residual noise etc.

In terms of the subsequent distribution of the source sound power for the purposes of noise mapping, the

research established that the most accurate way of modelling a noise source is by distributing the sound

energy in a manner as similar as possible to the real situation. However, where this is either not practicable,

or the true sound power distribution is not known, a reasonable degree of accuracy can be obtained by

modelling the sound power as either a 2 dimensional area source or a point source.

AT5414/2 Rev 1 Acoustic Technology 13th October 2003

i

The results of the modelling also indicated that the directivity of the source can significantly influence the

accuracy of the noise contour values. For this reason, the proposed method includes provision for

determining the acoustic centre and directivity of the source.

Research has also been conducted to investigate the potential errors incurred by utilising the overall A-

weighted (single band propagation) terms defined in ISO 9613. Whilst calculations based on octave band

frequency data give greater accuracy, a single figure calculation is the preferred option and would be more

consistent with the mapping of other sources. The results of the modelling show that, in general, a single

band approximation of the propagation of sound offers a relatively accurate approximation for industrial noise.

It has therefore been recommended that the mapping of industrial noise for strategic purposes be conducted

using overall dB(A) values, with attenuation terms for the 500 Hz octave band being used to estimate the

resulting attenuation.

Measurements were conducted at two sites to provide data to assist validation of the model. A variety of

close proximity and far field measurements were conducted to allow the relative accuracy of different methods

to be determined.

It is concluded that the proposed methodology allows consistent and reasonably accurate representation of

industrial noise sources for strategic noise mapping purposes. This will provide the necessary firm basis for

assessing the effects of industrial noise and mitigation where this is considered necessary.


ii

CONTENTS

1. INTRODUCTION Page 1

2. AIMS AND OBJECTIVES Page 1

3. DOCUMENT REVIEW Page 2

4. PROJECT CONSULTATION Page 9

5. REVIEW OF NATIONAL DATASETS Page 21

6. REVIEW OF SOUND PROPAGATION CONCEPTS INCLUDING EFFECTS OF

TEMPERATURE AND RELATIVE HUMIDITY

Page 23

7. DETERMINATION OF SOURCE NOISE LEVEL Page 27

8. SITE INVESTIGATIONS 2

9. RECOMMENDED METHODOLOGY FOR SOURCE NOISE LEVEL DETERMINATION Page 69

10. RECOMMENDED MEASUREMENT METHOD Page 71

11. APPLICATION OF DATA Page 85

12. CONCLUSIONS Page 86

REFERENCES

GLOSSARY OF TERMS

APPENDIX 1: Local Authority Questionnaire

APPENDIX 2: Stakeholder Contact Letters

APPENDIX 3: European Government Departments Contact Letters

APPENDIX 4: List of Local Authorities Who Responded To Questionnaire

APPENDIX 5: Review of National Databases

APPENDIX 6: Results of Relative Humidity and Temperature Review Calculations

APPENDIX 7: Noise Modelling Summary Sheets – Point Source

APPENDIX 8: Noise Modelling Summary Sheets – Building With Even Radiation

APPENDIX 9: Noise Modelling Summary Sheets – Building With Directional Radiation

APPENDIX 10: Noise Modelling Summary Sheets – Two Buildings With Directional Radiation

APPENDIX 11: Noise Modelling Summary Sheets – Four Buildings With Directional Radiation

APPENDIX 12: Noise Modelling Summary Sheets – Point Source Between Buildings

APPENDIX 13: Noise Modelling Summary Sheets – Point Source on Roof of Building

APPENDIX 14: Noise Modelling Summary Sheets – Point Source on Stack

APPENDIX 15: Noise Modelling Summary Sheets – Industrial Zone

APPENDIX 16: Noise Modelling Summary Sheets – Open Site


iii

LIST OF FIGURES

Figure No. Title Page No. 1 Comparison of Geometrical Correction Determined by Stüber method and EEMUA 6 2 Summary of the Range of Industries Identified in LA Response 10 3 Weighted Summary of the Range of Industries Identified in LA Response 10 4 Summary of the Percentage of Sites with Characteristics 11 5 Graphical Representation of Calculation Method 34 6 Calculation Method for Point Source 35 7

Calculation Method for Building with Even Radiation – Re-Modelled by Smearing the Calculated Sound Power Level Equally Over Each Façade

38

8

Calculation Method for Building with Even Radiation – Re-Modelled as a Point Source

38

9

Calculation Method for Building with Even Radiation – Re-Modelled as a 2D Area Source

39

10

Calculation Method for Building with Directional Radiation – Re-Modelled by Smearing the Calculated Sound Power Level Equally Over Each Façade

41

11

Calculation Method for Building with Directional Radiation – Re-Modelled as Point Source

42

12

Calculation Method for 2 Buildings with Directional Radiation – Re-Modelled by Smearing the Calculated Sound Power Level Equally Over Each Façade

44

13

Calculation Method for 4 Buildings with Directional Radiation – Re-Modelled by Smearing the Calculated Sound Power Level Equally Over Each Façade

46

14

Calculation Method for Point Source Between 2 Buildings – Re-Modelled by Smearing the Calculated Sound Power Level Equally Over Each Façade

48

15

Calculation Method for Point Source on the Roof of a Building – Re-Modelled by Smearing the Calculated Sound Power Level Equally Over Each Façade

50

16

Calculation Method for Elevated Point Source – Re-Modelled by Assuming Point Source at Lower Height

52

17 Relationship Between Adjacent Sources Showing Influence on Lw Determination 54 18

Calculated Error for Measurement of Sound Power Level of Extended Sources as a Relationship of Angle Subtended Between Adjacent Sources

55

19 Worked Example – Extended Source 56 20

Calculation Method for Combination of Several Source / Screening Concepts – Re-Modelled as a 2D Area Source

58

21

Calculation Method for Combination of Several Source / Screening Concepts – Re-Modelled as a Point Source

58

22

Graphical Representation of Site Layout for Combination of Several Source / Screening Concepts

59

23 Graphical Representation of Oil Gathering Station Cadna Model 60 24

Difference in Calculated Sound Pressure Level Between Hard and Soft Ground Calculations For Oil Gathering Station Model

61

25 Community and Boundary Measurement Locations – Factory Unit Tests 64 26 Measurement Positions – Open Site Tests 67 27 Measurement Positions for Close Proximity Method 75 28 Worked Example – Close Proximity Method 79 29 Measurement Positions for Distant Measurement Method 80 30 Worked Example – Refined Distant Method 83


iv

LIST OF TABLES

Table No. Title Page No.1 Summary of LA Responses 9 2 Number and Percentage of Sites Identified with Various Characteristics 11 3 Normalisation Values for Spectrum Shapes 25 4 Example Spectrum Shape for Falling Spectrum for 100 dB(A) Overall Level 25 5 Summary of Results for Deviation for Extremes of Temperature and Relative Humidity 26 6

Comparison of Sound Power per Square Metre for Various Types of Industry in Holland

28

7 Comparison of Sound Power per Square Metre for Container Terminals in UK 28 8 Comparison of Sound Power Level per Unit Throughput for Various Gas Terminals 31 9

Comparison of Sound Power Level Determination for Full Octave and Single Band Calculations for Factory Unit Tests

65

10

Comparison of Calculated Sound Pressure Levels With Measured Values for Factory Unit Tests

65

11

Comparison of Calculated Sound Power Level for Different Methods of Determination –Open Site Tests

68

12

Comparison of Calculated Sound Pressure Levels with Measured Values Using Full Octave Band Calculations - Open Site Tests

68

13

Comparison of Calculated Sound Pressure Levels with Measured Values Using Single Band Calculations - Open Site Tests

69

14

Suggested Methods of Representing Different Types of Industrial Source for Noise Mapping

85


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1. INTRODUCTION

The Department for Environment Food and Rural Affairs, Defra, has commissioned Bureau Veritas

Acoustic Technology (BVAT) to undertake a research project to investigate the assessment of noise

from industrial sources to assist in its noise mapping processes.

This final report presents the work conducted during the project, the findings of each of the main tasks

and draws conclusions from those findings.

2. AIMS AND OBJECTIVES

The aims of the project were specified in the invitation to tender (ITT) as follows:

• to develop a methodology for mapping sources of industrial noise as part of the first phase of

noise mapping;

• to ensure that the methodology developed will integrate fully with national databases and

reflect relevant GI data management issues.

The ITT stated that the aims of the projects would be met by the following objectives:

• understanding Defra’s requirements for noise mapping to meet the EU Directive 2002/49/EC

(Reference 1);

• familiarity with the interim computational method for assessing noise from industrial sources

set out in Directive 2002/49/EC;

• devising a method for representing industrial sources in the noise model; this method must be

simple, reproducible and robust;

• making recommendations to Defra on the most appropriate method that meets the industrial

noise requirements of Directive 2002/49/EC;

• ensuring the methodology developed is fully compatible and consistent with national

databases and other relevant GI data management issues;

• anticipating that, in general terms, the methodology eventually adopted will fall between the

following bounds:

representation of an industrial site by modelling a single point source located at the

centre of the site and,

representation of an industrial site by modelling every noise source that exists on the

site to a high level of spatial and acoustic accuracy.


1

Each of these issues has been addressed fully in the course of the project and is reported herein.

3. DOCUMENT REVIEW

3.1 National Ambient Noise Strategy

Defra’s Consultation Paper “Towards a National Ambient Noise Strategy” (Reference 2) sets out the

Government’s proposals for developing a National Ambient Noise Strategy for England. A three-

phase approach is described which would result in Government setting the necessary policies to allow

a strategy to be implemented. The first phase of the proposals aims to gather information on the

following issues:

• The ambient noise climate in the country;

• The adverse effects of ambient noise;

• The techniques available to improve poor areas and preserve good;

• The methodology to be used to undertake economic analysis.

The development of a standardised approach on how to map sources of industrial noise is important

to the first of these, as the UK has no national approach or standard. A simple methodology, which

allows consistent and reasonably accurate representation of industrial noise sources for noise

mapping, will provide the necessary firm basis for assessing the effects of industrial noise and

mitigation where this is considered necessary.

3.2 European Noise Directive

Directive 2002/49/EC defines a common approach, which is intended to prevent or reduce the harmful

effects to humans of environmental noise, including annoyance. It identifies three actions to be

carried out progressively;

• The determination of exposure to environmental noise through noise mapping;

• Provision of information to the public on environmental noise and its effects;

• Adoption of action plans based on the results of noise mapping with a view to prevention or

reduction, particularly where levels may induce harmful effects to humans and to preserving

areas of “good” environmental noise.


2

The Directive also requires the development of measures to reduce noise from transportation and

external industrial noise sources and mobile machinery.

The Directive requires the use of the day-evening-night level Lden and the night-time noise indicator

Lnight. Industrial noise in the UK is normally assessed in terms of resultant LAeq levels; however, it is a

simple conversion to the required indicators, if all relevant information is available.

Annex I of the Directive acknowledges that it may be necessary to use special noise indicators and

limit values. This is of particular interest as, unlike transportation noise, industrial noise can exhibit

distinctive characteristics, with tonal, low frequency or impulsive noise of special note. These

characteristics can often lead to annoyance at levels lower than those that would normally be

expected to be of concern.

The data to be sent to the Commission specified in Annex VI of the Directive requires Lden values

above 55 dB and Lnight values above 45-50 dB. This may act as a filter on the number of industrial

noise sources that will need to be included under the first phase of noise mapping. It is

acknowledged, that as industrial noise sources will need to be mapped separately to transportation

sources, the limit for industrial sources to be mapped will be lower than the total value.

The Directive’s further aim is to provide a basis for developing community measures to reduce noise

emitted by the major sources, including industrial equipment and mobile machinery.

3.3 ISO 9613-2

The European Noise Directive discussed above recommends ISO 9613-2: “Acoustics Attenuation of

sound propagation outdoors; Part 2 General Method of Calculation” (Reference 3) as the interim

computational method for industrial noise.

ISO 9613-2 is based on using octave band frequency source data to calculate resultant environmental

noise levels from source sound power levels. A simpler method for mapping industrial noise would be

to use overall dB(A) values and the standard does contains reference to such a methodology. The

standard states that:

“If only A-weighted sound power levels of sources are known, the attenuation terms for 500 Hz may

be used to estimate the resulting attenuation.”


3

Whilst it is clear that calculations based on octave band frequency data would give greater accuracy

and information (especially in terms of low frequency noise and tonality of sources), it is

acknowledged that a single figure calculation is the preferred option and would be more consistent

with the mapping of other sources, easier to use and would be likely to give a sufficient level of detail

for strategic mapping purposes. A method based on single figure calculations will also result in faster

calculation times and easier data handling. The relative benefits and disadvantages of octave band

frequency versus single figure calculations have been reviewed fully as part of the study.

The methodology developed will also need to take into account industrial sources that do not operate

for the whole of the periods of interest (day, evening, night).

As a specific requirement of this project a review has been conducted of the effect on sound

propagation values (and hence resultant noise levels) of different values of temperature and relative

humidity. The results of this review are presented in Section 5 of this report.

3.4 ISO 8297

This standard (Reference 4) specifies an engineering method for determining the sound power level

of multi-source industrial plants for the assessment of noise in the environment. This method was first

proposed by Stüber in 1972 and submitted to ISO for consideration as a standard in 1982. The

standard states that the method is applicable to industrial areas where most of the equipment

operates outdoors, not enclosed by a building. This would exclude a large number of manufacturing

plants, unless the view was taken that the noise sources of concern in this situation are more likely to

be those that are external to the factory building. It is applicable to industrial plants in which the

largest horizontal dimensions of the plant area lie between 16 m and 320 m. However, it is

understood that these limitations are based on the limits of the measurement exercises carried out by

Stüber when developing the method, rather than acoustical or physical constraints.

The standard is based on the measurement of sound pressure levels on a closed path surrounding

the plant with individual sources within the site treated as a single source at the geometrical centre of

the plant. The standard states the data obtained by this method is suitable for use in determining

contributions of industrial areas to sound pressure levels in the surrounding environment, however it is

limited to large multi-source plants with noise radiation substantially uniform in all directions.

Some aspects of practical use of the standard are worthy of discussion as follows. The standard

requires measurement of sound pressure levels on a closed path surrounding the plant, thus requiring

access to all sides of the industrial plant. The allowable distance of the measurement points to the


4

perimeter of the noise sources is very precisely defined, varying from 5 m to 35 m, with a precisely

defined spacing between the measurement points. In the majority of cases, measurements on a fully

closed path would be difficult to achieve, depending on the available access to the industrial site.

Often industrial plants are located adjacent to other private properties with no intervening public

access. As stated above, the measurement contour needs to meet specific requirements, which

would require some assessment prior to mobilising to site. If access difficulties were then

encountered, a new measurement contour would need to be defined and assessed against those

requirements. This would be difficult to do on site and may involve a repeat visit.

The height of measurements around the industrial plant needs to be determined from the average

height of the sources on the site. This would need to be obtained from equipment lists and site plans

and elevations prior to mobilising to site. In addition, some assistance might be obtained from height

databases, although it should be recognised that the height of individual buildings would not

necessarily reflect the height of all the major noise sources on a site.

The standard requires measurements to be made at a height, determined by:

mSHh m 5025.0 ≥+=

where H is the average height of the plant’s noise emitting equipment and Sm is the measurement

area. This equation is derived based on an assumed radius of curvature for sound of 5000 m (i.e.

assuming an average wind gradient of 7 ms-1 per 100 m, irrespective of height).

For large industrial sites, the measurement height would be impractical. For example, a 1 km2 site

would require a measurement height typically greater than 30 m, and this would increase to more than

55 m for a 4 km2 site. This implies that the measurement method would need some modification if it

were to be extended for use on large-scale sites. The standard does allow for this and states that the

microphone should be placed as high as possible above the minimum height of 5 m.

Industrial plants may be located adjacent to other significant noise sources (i.e. main roads, other

industrial plants). It is often not possible to conduct measurements to separate contributions from the

industrial and other sources and hence the standard’s requirement for background noise levels 6 -10

dB lower than the industrial source may be difficult to achieve and even where it could be achieved,

may be difficult to demonstrate.

The standard requires that, where the industrial plant contains individual noise sources that are

significantly elevated above ground, these should be identified and measured individually to


5

determine their sound power levels. This requires a reasonably detailed knowledge of the site and

would require access onto the site. Sound power level determination of elevated sources can be

complex, sometimes involving the use of “cherry pickers” and cranes to gain access.

The average sound pressure level along the measurement contour is then combined with a relatively

complex area term, and other correction factors to take into account proximity to the grouped noise

sources, atmospheric absorption and a microphone correction factor (if omni-directional microphones

are not used). Due to the practical difficulties of the methodology set out in this standard, it is

considered that it would not be appropriate to specify the full use of this standard for the purposes of

strategic noise mapping. However, it is envisaged that a simplified version of this standard could be

used to measure sound power levels for mapping purposes.

Appendix C of EEMUA Noise Procedure Specification, Publication 140 (Reference 5) contains a

simplified version of the Stüber method. The EEMUA version does not specify such stringent

requirements on the measurement height and distance etc. The main difference is, however, the

geometric near-field error term, which is based upon Stichting Concawe Report No. 2/76,

“Determination of Sound Power Levels of Industrial Equipment, Particularly Oil Industry Plant”

(Reference 6). In this case, the geometrical near-field error is based upon the angle subtended at the

microphone position by the source. For convenience, this can also be determined by the quotient, Q,

of the plant area to the measurement area. Figure 1 shows the values of error determined using the

EEMUA method, plotted against the errors determined in ISO 8297:

0

1

2

3

4

0 0.2 0.4 0.6 0.8 1 1.2Q

Geo

met

rical

Cor

rect

ion,

dB

Stüber Correction

EEMUA Correction

8

FIGURE 1: Comparison of Geometrical Correction Determined by Stüber method and EEMUA


6

It can be seen from Figure 1 that the geometrical near-field correction recommended in EEMUA is in

fact a simplified approximation of the values derived via the Stüber method.

3.5 ISO 3744 & ISO 3746

These two standards (References 7 and 8) present similar methodologies for determining source

sound power levels from measurements over a reflecting plane to engineering grade and survey

grade of accuracy respectively. They are suitable for use with a single source and require

unrestricted access to the source.

Most industrial sites, where noise is a consideration, consist of several noise sources and these

methods for sound power level determination would require relatively detailed measurement of each

individual source. Access to industrial sites is not generally available without prior arrangement and

this can often be time consuming.

Whilst these methods are suitable for many applications, it is considered that for the purposes of

strategic noise mapping, they are not suitable for larger industrial developments, and are too complex

and time consuming. In principle, it is felt that adherence to these more detailed methods of sound

power level determination for individual noise sources may be appropriate if, as a result of the initial

strategic noise mapping exercise, a more detailed assessment of the noise radiation characteristics of

the industrial site was deemed to be required.

3.6 Good Practice Guide on the Sources and Magnitude of Uncertainty Arising in the Practical

Measurement of Environmental Noise

This document (Reference 9) was published by the University of Salford in October 2001 and aims to

present the uncertainties arising in measurement of environmental noise in as simple a manner as

possible. It is intended to enable users to define probable sources of uncertainty and to determine the

magnitude of those uncertainties.

The document proposes a procedure for formulating uncertainty budgets by considering the

measurement chain in three sections i.e. source, transmission path and receiver. The uncertainty for

each section is then combined to provide an overall uncertainty, which can be expanded to give 95%

confidence. A flowchart is provided for the procedure along with a checklist to assist with the

identification of sources of measurement uncertainty.


7

As part of the study, controlled measurement exercises were conducted to investigate the lower limits

of uncertainty. These measurements showed significantly greater uncertainty in reproducibility (same

source and measurement procedure but different operators, equipment and times) than repeatability

(same source, equipment, method and operator within short time interval). Further examples are

provided of determination of uncertainty for real measurement exercises.

The principal potential sources of uncertainty in noise measurements, under the three sections

identified previously, are as follows:

Noise Source

Spectral content;

Point/line/area source;

Operating conditions;

State of repair of source;

Source height;

Static/mobile sources;

Enclosures/barriers close to source;

Weather.

Transmission Path

Weather;

Ground effects;

Barriers.

Receiver

Microphone position (height, orientation, reflecting surfaces);

Instrumentation/calibration;

Background noise.

Each of these potential sources of uncertainty is discussed with “Good practice guidelines” and

“Useful notes” included where appropriate.


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4. PROJECT CONSULTATION

4.1 Local Authorities

A questionnaire was sent to the Principal Environmental Health Officers of all Local Authorities in

England. This was followed on two occasions by an email reminder. A copy of the questionnaire and

the covering letter are included in Appendix 1 of this report. The questionnaire was intended to assist

in the identification of the range and composition of industrial noise sources in England. It asks for

identification of the three main industrial noise sources in each region and, where information is

available, the level and type of noise they emit.

A reasonable response was received and this is summarised in Table 1.

Number of questionnaires sent: 368

Number of responses to July 2003: 166 45%

Number of responses with NO major industrial noise sources within their area: 43 12%

Number of authorities who indicate that they hold noise data for industrial sites: 83 23%

Number of authorities who included noise data in their response: 12 3%

TABLE 1: Summary of LA Responses

The questionnaires returned identified some 300 industrial sites across England that the Local

Authorities considered noise from the sites to be affecting their areas. Of those 300 sites,

approximately half (147 sites) were considered to be significant sources of noise in that area.

The range of industries identified is shown in Figure 2, overleaf.


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Other

Production and processing of metals

Food Industry (inc. drink / bottles)

Manufacturing industryIndustrial Estates (Mixed)Chemical plants

Power stations

Mineral processing

Car and transport manufacturing

Mineral extraction sites

Ports

Waste transfer stations

Wood mills

Warehouse and distribution

Paper millsPrinting

Landfill sites / waste to energy schemes

Waste incineratorsGas terminals

Sewage works

Oil refineriesCoke ovens

Cement mills

FIGURE 2: Summary of the Range of Industries Identified in LA Response

*

In order to place emphasis on those industries that were considered to be significant sources of

environmental noise in a particular area, a scoring system of 2 was given to these industries, with the

other entries being given a score of 1. This rating is reflected in the Figure 3.

Production and processing of metals

Other

Food Industry (inc. drink / bottles)

Manufacturing industryIndustrial Estates (Mixed)Chemical plants

Power stations

Car and transport manufacturing

Mineral extraction sites

Mineral processing

Wood mills

Waste transfer stations

PortsPrinting

Paper mills

Warehouse and distribution

Gas terminals

Waste incinerators

Landfill sites / waste to energy schemes

Cement mills

Sewage worksOil refineries

Coke ovens

*

FIGURE 3: Weighted Summary of the Range of Industries Identified in LA Response

* ‘Other’ includes: Airfields / Airports, Brickworks, Bus Depots, Civic Amenity Centres, Drycleaners, Dyeworks, Glassworks, Motor Speedways, Petrol Stations and Train Depots.


10

The questionnaires also requested information regarding the characteristics of the major industrial

sources, and the response is summarised in Table 2 and Figure 4, below.

Number and percentage of sites with tonal characteristics: 153 51 %

Number of sites with impulsive characteristics: 114 38 %

Number of sites with low frequency characteristics: 111 37 %

Number and percentage with no characteristic: 65 22 %

Number and percentage with just one characteristic: 123 41 %

Number and percentage with two characteristics: 81 27 %

Number and percentage with all three characteristics: 31 10 %

TABLE 2: Number and Percentage of Sites Identified with Various Characteristics

Sites with no characteristic

Sites with only one characteristic

Sites with two characteristics

Sites with all three characteristics

FIGURE 4: Summary of the Percentage of Sites with Characteristics

A degree of caution must be expressed in the interpretation of these results, as some Local Authority

areas will be heavily industrialised as compared to others. Thus the pie chart in Figures 2 and 3,

above, should not be used as a direct indication of the percentages of the different types of industry

throughout England that are considered as major sources of noise, but only as an indication of the

range of industries that Local Authorities believe are significant in their area.

Further contacts were made with the local authorities, which indicated that they might have had useful

data. This was targeted to represent a cross-section of the main industries identified by the feedback

from LA’s.


11

A list of the local authorities that responded to BVAT’s questionnaire is included in Appendix 2. There

were several authorities that did not reply but where BVAT is aware of significant industrial noise

sources affecting their area. However, no attempt was made to target specific authorities with

reminders because this could ‘skew’ the data.

4.2 Stakeholders

4.2.1 Stakeholder Contacts

Early in the project, initial contact was made with the following stakeholders to inform them that BVAT

was undertaking this research.

Environment Agency – Lesley Ormerod

CBI – Janet Asherson

CIEH – Howard Price

CPRE – original contact Abigail Jermain, now Rebecca Richings

NSCA – Mary Stevens

The NSCA was included as CPRE cited them as a more relevant stakeholder - as CPRE follows

NSCA guidance on noise issues.

This was followed up in May 2003 with further information regarding the content of the project to allow

stakeholders to express any opinions on the main aspects of the research. Copies of both letters sent

to the stakeholders are reproduced in Appendix 3.

With the exception of the Environment Agency (see below), no formal responses were received from

any of the stakeholders.

4.2.2 Environment Agency

More detailed contact has taken place with the Environment Agency. Initial telephone discussions

took place to ensure that any issues that they consider to be critical were addressed. From these

initial discussions, it was clear that the EA considered it very important to research the following

issues:


12

• the merits of using a methodology based on overall single figure dB(A) levels versus octave

band calculations;

• accounting for character of industrial noise e.g. tonality, low frequency, impulsiveness etc;

• the validity of using non-acoustic means to generate sound power levels for industry.

Whilst it was acknowledged that the methodology proposed under the current project would be used

for strategic noise mapping, concerns were expressed regarding the significance of local site

variations being lost within a simplified methodology. This related to the character of industrial noise,

which was considered to be a significant factor in response to that noise in the environment. Also in

relation to the use of non-acoustic means, concern was expressed that this method would not account

for the considerable variations that can occur between similar industries within this country. For

example, the level of noise from an industrial source can often depend on the proximity of noise

sensitive receiver locations to it.

The EA considers that there are no industries that fall under IPPC legislation that could readily be

identified as being of low concern with regard to noise issues. Experience has shown that variation

within sectors is such that all applicants for permits are required to demonstrate that a plant is

inherently quiet for a full noise assessment to be avoided. Where sites already exist, the EA always

requires measurements to be conducted rather than relying on the results of acoustic modelling.

Another issue raised by the EA is the concern that any methodology derived for strategic mapping of

industrial noise sources would be used out of context where a more detailed assessment should be

undertaken e.g. in an application for a permit under IPPC. It was requested that, should BVAT

propose a simple methodology, clear guidance be given as to where its use is appropriate.

In June 2003 a meeting took place between representatives of BVAT, the EA and Defra. The

following items were discussed at this meeting:

Background to the study Defra provided a short presentation detailing why this research is

being undertaken as well as general background information about

other activities taking place in parallel.

Presentation overview BVAT presented an overview of the project and issues being

considered, including a synopsis of modelling methods being

developed for the project.


13

Databases BVAT summarised the LA responses to date and gave an overview

of the statistical analysis carried out.

Additional concerns The EA reiterated concerns about providing a clear scope / guidance

on the appropriate use of any simplified methodologies developed.

Of particular concern was any conflict with IPPC applications. BVAT

and Defra agreed that such guidance would be prudent to prevent

confusion.

4.3 European Contacts

4.3.1 European Government Contacts

The following European governmental departments have been contacted to determine relevant

standards or guidelines in use in these countries for mapping industrial noise sources. The letters

sent are reproduced in Appendix 4.

German Federal Environment Agency - Volker Imer

Danish Environmental Protection Agency - Hugo Lyse Nielsen

French Ministry of County Planning and Environment - David Delcampe

Dutch Ministry of Housing, Spatial Planning and the Environment - Martin Van den Berg

Other similar contacts made include TNO1 in the Netherlands and Müller BBM2 in Germany. Initial

letter contacts were followed up during the project with email reminders.

4.3.2 Relevant EU research

It is understood that research is underway at a European level regarding issues relevant to mapping

of industrial noise sources. These include the adaptation and revision of the interim computation

methods for the purposes of strategic noise mapping, and the preparation of tool kits for noise

mapping different sources of noise. However, it is understood that none of these tool kits were

relevant to this project.

Another item of research in the UK that may be of relevance, is the work being undertaken to define

“best practice” in noise prediction for surface mineral workings in consultation document MPS2. It is

1 TNO - Nederlandse Organisatie voor Toegepast 2 Müller BBM GmBH is a German engineering consultancy company


14

also understood that there is another area of research in the UK into “quiet areas”, and this may have

some relevance to the present study.

4.3.3 Review of European Countries

Defra publication of June 1999 “Noise Climate Assessment: A Review of National and European

Practices” (Reference 10) contains a comprehensive review of legislation in European countries other

than the UK at that time relating to noise and the environment within the context of strategic noise

mapping. It is acknowledged that this document is somewhat out of date; however, it does give a

useful indication of the techniques in use in recent years in those countries, albeit these techniques

have been in use in the period preceding the publication of the EC noise mapping directive.

The following paragraphs give BVAT’s initial findings on methodologies in use in other European

countries in relation to industrial noise.

Netherlands

The Defra publication found that the Noise Abatement Act 1979 required noise zoning close to new

roads and industrial areas by 1982. During the authorisation process, noise models were being used

to establish noise zones in which particular industrial activities could take place. Industrial noise had

been mapped for around 1200 industrial zones. In noise mapping of industrial sources, standard

calculation methods were in use to calculate noise emissions based on non-acoustic means i.e. class

of industry and post-code. Noise limits were in place for industry and for new residential development

close to existing industry. It is noted that, at that time, TNO was undertaking research into integrated

noise mapping systems.

A response has been received from the Dutch Ministry of Housing, Spatial Planning and the

Environment in the Netherlands. Martin van den Berg has confirmed that considerable work has been

undertaken over recent years to determine the impact of industrial noise and that noise zones have

been calculated around approximately 1000 major industrial areas. This was done using the

calculation procedure described in the Noise Abatement Act. He was unable to provide details of this

procedure, but provided a number of further contacts, see below, who he considered were likely to be

able to assist further.

DCMR Technical Environmental Services Rotterdam area, Henk Wolfert

DGMR Acoustic Consultants, Hans van Leeuwen

RIVM National Institute for Health and Environment, Ton Dassen


15

Henk Wolfert referred BVAT to his colleague Astrid van Wijk, who has undertaken a considerable

amount of work in this field.

Generally, the Netherlands has industrial zones but some areas have industry outside these zones.

Most mapping is the responsibility of the industrial operators themselves. For mapping industrial

noise, source noise levels supplied by equipment manufacturers are used and are supplemented with

measurement where necessary. Manufacturers are required by law to provide sound power data and

this is therefore readily available. Individual noise sources are mapped with detailed knowledge of the

site. Where measurements are required, these are usually carried out by acoustic consultants and

are detailed measurements of individual sources rather than global boundary or community

measurements. A propagation model is then used, based on a Dutch standard, which is similar but

not identical to ISO 9613.

The planning regime has two procedures. Where industry is to be developed within an industrial

zone, then it is allocated an allowable sound power level per unit area and an allowable sound

pressure level at the nearest property. It is then up to the industry to design the plant to make best

use of their noise allowance e.g. using buildings to screen towards residential properties. If

development is proposed for outside an industrial area, then it is required to use ALARP3 and usually

has an overriding limit of 50dB(A) at the nearest property, although often a lower limit is set if this is

considered achievable.

A further response was received from Rob Witte of DGMR, who has carried out some research on

non-acoustic means of determining the sound power levels of industrial premises. This work is

presented in Section 7.2.1, below.

Denmark The Defra research paper indicates that in Denmark, limits were set for environmental noise based on

Best Available Techniques (BAT). Guidelines were in existence, one of which, Guideline No. 6,

described methods for measurements of noise from industrial plants. A further guideline was

published in 1993 on the calculation of noise from industrial plants. The requirements placed on an

industrial noise source varied depending on the surrounding area.

3 As Low As Reasonably Practicable


16

Although noise mapping had been undertaken for transportation sources, nothing similar was in place

for industry. Transportation noise mapping was generally based on noise prediction rather than noise

measurements. A limited number of industries, or recreational sources were required to have noise

zones (shooting and motor sport). Some gas processing plants were also understood to use the

program SoundPlan to determine environmental noise levels.

The Danish Acoustical Institute published a report (No. 105) in 1983 entitled “Noise Immision from

Industry – Measurement and Prediction of Environmental Noise from Industrial Plants.” (Reference

11). It compared four methodologies for global measurement of sound power levels of entire

industrial plants. The measurements were conducted in 1982 around an asphalt plant with more

limited measurements around an oil refinery.

The first of these was the General Nordic Short Distance Method. This involves measuring sound

pressure level on a box-shaped measurement surface which envelopes, and is close to the source.

Measurements are conducted at a number of heights depending on the source height (2.2 m and 12.5

m for this case). The sound power level is then determined from the sound pressure level (corrected

for environment) integrated over the area of the measurement surface, with a near field correction

applied.

The General Nordic Long Distance Method requires sound pressure level measurements on a

hemisphere around the source at a minimum of four equally spaced positions on the circle (at a height

of up to 10 m). Sound power level is then determined by integrating the sound pressure levels over

the measurement surface and with corrections applied for directivity.

The Nordic Large Source Method is designed for determination of sound power level of very large

industrial plants. This method is more flexible than the general methods as measurements are

conducted at greater distances from the site and need not necessarily be conducted on all sides of

the source. Measurements are conducted at a height between 5 and 10m and are normalized to a

free field sound pressure level at 1m from the centre of the source by backward application of the

General Prediction Method. The normalised sound pressure levels are averaged and a sound power

level calculated along with corrections for directivity. Meteorological conditions necessary for the

method are specified and an integration time of at least 10 minutes is recommended.

The final method investigated was the Stüber Method (which has formed the basis for ISO 8297) and,

as such, has already been considered in Section 2.


17

Sound power levels were then determined for individual sources on the site by detailed measurement.

Comparison of the methods found that the levels determined by the general long distance method, the

large source method and the Stüber method all agreed within a few dB. It was found that the general

Nordic Short Distance Method gave consistently higher results (1 – 4 dB) than the others due to a

geometrical error inherent in the method.

France

The Defra research paper indicates that although noise studies were undertaken to predict the impact

of industry on environmental noise levels, no significant research has been undertaken regarding

industrial noise sources for the purposes of strategic noise mapping. It is understood that a number of

towns have produced local noise maps, including Paris whose results have been published on the

Internet.

Bureau Veritas met with “le Ministère de L'écologie et du Développement Durable” (The Ministry for

Ecology and Durable Development) on the 25th June 2003 to discuss mapping of industrial noise.

The French ministry indicated that there was no specific method developed or in development for

mapping of industrial noise. Noise measurement data exists for industrial sites under French law and

noise mapping in France will therefore use this existing data. However, it is not known how the

French authorities will utilise these existing noise measurement data to produce industrial noise maps.

The Paris noise map was carried out by the “Service Technique de l'Ecologie urbaine” (Engineering

Department of Urban Ecology), a department of French local government. However, this does not

include noise from industrial sources. It is not known whether the map will be developed further to

include industrial noise.

Germany

From the Defra research paper it is known that considerable noise mapping had been undertaken in

Germany, however this had focussed on transportation noise. Because noise maps are currently

widely used in Germany, they are commonly used to designate permitted noise levels for proposed

industrial developments. Noise levels for industry are therefore subject to strict limits (TA Lärm).

Hence, there are currently two methods used for mapping industrial noise in Germany:

i. Measurements can made of noise emission from industrial sites to establish an overall sound

power level.


18

ii. Alternatively, the overall noise emission of a site can be determined in terms of a sound

power level per square metre. This information would be available in the case of new

premises and is particularly used to designate permitted emissions from proposed facilities.

Because noise maps have normally been used to designate limits, the latter method of determining

sound power levels can be easily applied. In other cases, it is necessary to undertake

measurements.

4.4 Birmingham City Council

Birmingham City Council, through its Environmental Services Committee and its active involvement

with EC Noise Policy, has been instrumental in the UK in pioneering the feasibility and benefits of

undertaking city noise mapping. Using the services of a German consultancy deBakom, in 1999, a

noise map of the City of Birmingham was produced.

For the area mapped, industrial noise was not considered to be a major noise source in comparison to

transportation and hence an in-depth assessment was not conducted. Industrial sites included in the

project were selected using Birmingham City Council’s knowledge of the area, choosing large

industrial plants that may have previously or currently had some noise issues associated with them.

Noise measurements were conducted at the majority of these sites. For these, sound power levels

were determined by measuring noise levels at a small number of measurement locations, from public

access locations. Measurements were conducted at a height of 10 m to reduce the effect of localised

screening. It is also understood from discussions with Birmingham City Council, that all measurement

locations had line of sight to the industrial plant. A distance to the centre of the source was assumed

and a corresponding sound power level determined. These sound power levels were then placed

along factory facades and roofs in the model and it is understood that a degree of “adjustment” was

necessary in this procedure to ensure that the computed noise contour values equalled the measured

sound pressure level values at the measurement locations.

All measurements were taken using the LA95 noise index, to minimise interference from non-industry

related intermittent noise sources. It is understood that no attempt was made to correct the LA95

measured values to obtain more typical LAeq values due to the industrial site. It is also understood that

no attempt was made to correct for background noise. A pragmatic approach was taken that, if the

noise from the site could be clearly heard, then it could be measured. With the exception of one site

where continuous measurements were made (railway shunting site) measurements were taken during

the daytime or evening periods. Sample lengths were typically 10 minutes long.


19

All contour calculations were undertaken in overall A-weighted values, although samples of noise

were tape-recorded and A-weighted narrow band analyses are included in the deBakom report. An

assumed value of 2 dB per 1000 m was used for air absorption for industrial noise. Ground effects

were not included in the calculations. No attempt was made in the mapping exercise to quantify, in

any sense, some of the industrial noise characteristics that often give rise to concern (e.g. tonal,

impulsive, low frequency). For sites where measurements were not conducted, levels were assumed

to be 10 dB lower than the background due to traffic.

For all the sites where measurements were taken, night-time sound power levels were taken to be

similar to daytime noise levels with the exception of shunting activities at the Rover site. For some

chosen sites, it was not possible to measure noise from the industrial site, due to the presence of

background noise from other sources (mainly traffic). In this situation, the assumption was made for

the purpose of deriving the industrial noise map of Birmingham, that the ambient noise level due to

the industrial site was 10 dB(A) less than the background level due to road traffic. It is understood

that no contact was made with the industrial site concerned to ascertain plant operating conditions at

the time of the measurements.

Calculated overall sound power levels at the various industrial sites where measurements were made

varied from 93 dB(A) to 116 dB(A). An accuracy of +/- 2 dB on the derived sound power levels is

claimed in the report, although the basis for the claimed degree of accuracy is not stated.


20

5. REVIEW OF NATIONAL DATASETS

5.1 General

As part of the research project, a review of national datasets has been carried out. The results of this

research at the time of this review are presented in detail in Appendix 5, and is summarised below. It

should be noted that national datasets are constantly being updated and that the information

contained in this section will need to be constantly reviewed to ensure its future applicability.

5.2 Industrial Noise Mapping Data Sources

No nationally consistent building height dataset is available from which to contribute to industrial noise

mapping either from consideration of the heights of the industrial buildings, or the heights of the

buildings surrounding the industrial site. OS has announced its intention to add this as an attribute to

the OS MasterMap digital topographic database, but this is unlikely to be ready in the short term to

supply specific height information attached to building polygons.

In the absence of a nationally consistent building height data, a combination of approaches is likely to

be necessary to add height data. Research into the appropriate datasets in each locality is needed.

Commercially sensitive telecommunications data and MOD data may provide the most

comprehensive information (although this would need to be investigated further). This alternative

approach is likely to include a combination of existing attributed building height surveys and

processing of industrial areas with data derived from digital elevation models.

NEXTMap SAR4 data now has complete national coverage and appears to offer an opportunity for a

national source terrain and surface model dataset which is useful for both terrain and feature height

mapping, but within stated tolerances. These tolerances (0.5 – 1 m) would be more than sufficient for

industrial noise mapping. The surface models would need to be “differenced” from the terrain model

to capture feature heights.

It is also clear that more datasets are becoming available for urban areas, and before the industrial

noise mapping is undertaken, a search for new data releases should be carried out which would target

the few companies producing products in this field. Often these datasets of building heights are part

of a suite of products (e.g. Cities Revealed have both building class for residential properties and

4 Synthetic Aperture Radar


21

building height data for selected cities). London is a data rich city but other UK cities still do not have

full coverage.

It should be noted that the height of a building does not necessarily indicate the height of the noise

sources on an industrial site, thus height datasets may be more appropriate to sound propagation

modelling rather than industrial noise source modelling.

5.3 Population Data

Population datasets are based on the UK Census. The Census 2001 data for local areas, based on

the geographic framework of the Output Areas, was released in June 2003. It is of interest to note

that some 88% of Output Areas in the census contain between 110 and 139 households. This should

provide the appropriate product set to help to assess noise impacted areas, and to obtain an

approximation of the number of people exposed to particular noise levels.

5.4 Dwelling numbers

Census data offers a description of the dwellings and the nature of accommodation at the date of

Census, but will not identify the specific locations of accommodation, being reported at an aggregated

level of Enumeration districts or Output Areas. New 2001 Census data will be available to use with

industrial mapping projects. The Census data would not, however, be sufficiently detailed to identify

the intersection of noise contours with dwelling numbers, should this be deemed necessary, (this is a

requirement under the EU directive).

Data derived from OS topographic databases offer the best opportunity to accurately locate buildings

(either as point locations or footprints) but do not distinguish the nature of the building or whether

there are multiple dwellings within a building. New products being developed by OS, the National

Buildings Data Set would fill the gaps in classification and links between building boundaries and

address data. Commercial products may provide a more immediate solution, such as QuickAddress

and local data for selected cities is available from Cities Revealed. However, there is still a problem in

using these datasets to identify dwellings as certain types of structure are classified as buildings but

would not be dwellings, and other types are not included (temporary buildings and caravans etc)

which would be covered in Census data.


22

The Valuation Office maintains the database of rated listings for Council Tax, and this appears to offer

the best identifier of dwellings and occupancy. In order to spatially query this data it would be

necessary to link to AddressPoint or similar products to derive a point-based dataset. Further

negotiation would be needed with the Valuation Office to access this source.

A hybrid approach may be necessary to identify the actual number of dwellings within a locality and

updates based on new buildings would need to be checked at the local levels with the planning

authority. New datasets will become available within the future and planned databases from the

Valuation Office appear to offer a solution, but the terms of release of such data is not known.

6. REVIEW OF SOUND PROPAGATION CONCEPTS INCLUDING EFFECTS OF TEMPERATURE AND RELATIVE HUMIDITY

6.1 Sound Propagation

In the derivation of noise modelling concepts for industrial sources, it is necessary to have a

fundamental understanding as to how sound propagates from a noise source. This is in order to

quantify potential errors that simplified modelling techniques may introduce (e.g. just using A-weighted

levels rather than frequency dependent data). There are a number of attenuation mechanisms in

calculating a sound pressure level at a defined distance from a noise source based on a knowledge of

the sound power level of the source, or vice versa. These include:

(i) geometrical divergence of sound energy;

(ii) ground interaction effects;

(iii) absorption directly by the atmosphere;

In addition to these, barriers and topographical features will also provide an attenuation mechanism.

The first factor relates to the way in which sound energy dissipates with distance in a geometrical

fashion. In general, sound decays at a rate of 6 dB per doubling of distance from a ‘point’ source

although this factor is modified close to the source by the physical source size. Other factors may

also temper this generalised rate of attenuation with distance.

The ground interaction effect is a phase cancellation phenomenon caused by the destructive

interference of ‘direct’ rays and rays reflected from the ground. This effect is significant for a range of

mid-frequencies over acoustically soft ground (e.g. grassland, ploughed fields etc.) but is less


23

significant, and less frequency dependent, if the ground is acoustically hard (e.g. concrete, water).

The actual ground profile between source and receiver may also modify this phenomenon.

Wind and temperature gradients in the atmosphere play a very important part in modifying sound

attenuation characteristics. A positive vertical temperature gradient causes sound to be refracted

downwards, which enhances sound propagation. This type of temperature gradient, known as a

temperature inversion, frequently occurs just before sunset and extends to just after sunrise if skies

are clear. During the day, if it is sunny, a negative vertical temperature gradient occurs in the

atmosphere and sound is refracted upwards. If it is cloudy, the cloud acts as a blanket and the

temperature gradient tends to be more neutral. In reality, vertical temperature gradients in the

atmosphere can be complex and change from positive to negative or vice versa, giving rise to more

complex sound propagation conditions.

Sound is also refracted downwards, in a downwind direction, and upwards in an upwind direction.

The combination of wind and temperature gradients may lead to shadow zones upwind of a noise

source, where the source of noise may be seen, but not heard. In a downwind direction, downwards

sound refraction may modify the ground interaction phenomenon, and also, at longer distances, give

rise to sound focusing effects. Generalised models of sound propagation cannot take into account the

detailed structure of the atmosphere on a day-to-day basis, therefore some differences between

measurements and predictions must always be expected. The most stable sound propagation

direction is downwind of a source, and typically within a distance of about 1 km. It is for this condition

and for this range that the best correlation with standard sound propagation models would be

expected to occur.

Sound absorption by the atmosphere involves a “real” loss mechanism in that a direct transfer of

energy occurs between the acoustic wave and the constituents of the atmosphere. There are a

number of different attenuation mechanisms involved concerning thermal and viscous losses and

transfer of energy to nitrogen and oxygen molecules. The main factors influencing atmospheric sound

absorption are temperature and relative humidity. This is a frequency dependent phenomenon, with

the greatest effect occurring at high frequencies.

There are a number of currently available noise modelling software packages which take these factors

into account by use of the appropriate standards for sound propagation effects. In the course of this

project BVAT has used the noise modelling software “Cadna”.


24

6.2 Relative Humidity and Temperature Review

As part of the research into industrial noise modelling, BVAT has reviewed the sound attenuation

effect of the range of temperature and relative humidity values that may be expected to occur in

England for distances likely to be considered in industrial noise modelling. The approach taken was

to consider noise sources with different spectrum shapes and then calculate the resultant sound

pressure level over distances of 500 m, 1 km and 2 km, for a range of temperature and humidity

conditions which are provided as the default range in the Cadna software. The extremes used are a

temperature of -10˚C to 35˚C and relative humidity of 50% to 100%.

Different spectrum shapes have been considered. These include a spectrum decreasing at 3 dB per

octave, a flat spectrum across the octave bands, a spectrum increasing at 3 dB per octave, a

“humped” spectrum peaking at 500 Hz with a fall off of 3 dB per octave either side, and a “typical”

industrial spectrum. Specifically the spectra used, relative to overall dB(A) levels, are shown in Table

3.

Octave Band Centre Frequency Spectrum Shape

31.5 63 125 250 500 1k 2k 4k 8k

Falling spectrum, dB +9 +6 +3 0 -3 -6 -9 -12 -15

Rising spectrum, dB -27 -24 -21 -18 -15 -12 -9 -6 -3

Flat spectrum, dB -7 -7 -7 -7 -7 -7 -7 -7 -7

Humped spectrum, dB -14 -11 -8 -5 -2 -5 -8 -11 -14

Typical industrial spectrum, dB +17 +12 +4 -1 -3 -5 -9 -12 -16

TABLE 3: Normalisation Values for Spectrum Shapes

Example:

To produce a sound pressure level of 100 dB(A), the falling spectrum shape would comprise the

following octave band values, as shown in Table 4.

Overall, Octave Band Centre Frequency

dB(A) 31.5 63 125 250 500 1k 2k 4k 8k

100 109 106 103 100 97 94 91 88 85

TABLE 4: Example Spectrum Shape for Falling Spectrum for 100 dB(A) Overall Level


25

The predicted sound pressure levels for noise sources with these different spectrum shapes, for the

range and extremes of temperature and humidity considered, have been compared to predicted

sound pressure levels for more typical values of 10˚C and 70% RH. In this calculation a source height

of 2 m has been assumed and receiver heights of 2 and 4 m. Consideration of the variation in height

of the source or receiver is only relevant to propagation over soft ground.

The results of these calculations are given in Tables A6.1 and A6.2 in Appendix 6, and are

summarised below. These values are for propagation over a 2 km distance.

2 m Receiver Height 4 m Receiver Height

Spectrum Type: Max. Deviation,

dB(A) Mean Deviation,

dB(A) Max. Deviation,

dB(A) Mean Deviation,

dB(A) Flat -7.8 -1.8 -6.8 -1.7 Typical Industrial -2.3 -0.7 -2.3 -0.7 Humped -7.1 -1.5 -6.2 -1.3 Rising -11.2 -2.5 -9.8 -2.4 Falling -3.7 -0.9 -3.3 -0.9

TABLE 5: Summary of Results for Deviation for Extremes of Temperature and Relative Humidity

These show that for a typical industrial noise spectrum (similar to a falling spectrum shape) the

deviation in the results from assuming meteorological conditions of 10˚C and 70% RH, as compared

to actual temperature and relative humidity values is only -0.7 dB(A) on average across the range of

extremes, with a maximum deviation of -2.3 dB(A). (A negative deviation implies an overprediction of

noise levels). Higher deviations occur for non-typical industrial noise spectra, as would be expected.

For example a flat spectrum shape exhibits a maximum deviation of just under 7.8 dB out to a

distance of 2000 m (for -10˚C and 50% RH), and a rising spectrum shape gives a deviation of 11.2 dB

at a distance of 2 km.

In principle, these results indicate that there is no need to consider varying temperature and humidity

effects in strategic industrial noise mapping, as long as the spectrum shape is not abnormally high

frequency in content. It is thought likely that this would apply to very few, if any, industrial sites. It is,

of course, still necessary to utilise a generic value for atmospheric absorption effects in the

propagation models.


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7. DETERMINATION OF SOURCE NOISE LEVEL

7.1 Basic Concepts Fundamental to this research project is the investigation of the most appropriate method to determine

the strength of an industrial noise source (sound power level) to be used as an input parameter for the

strategic noise mapping process. In concept, three possibilities exist. These relate (i) to the

prediction of industrial source sound power levels through non-acoustic means; (ii) to the

determination of industrial source sound power levels through direct measurement of sound pressure

levels (or sound intensity levels), and then integrating the measured parameter with an assumed

radiation area term to give the sound power level of the source and (iii) a combination of the two

previous methods.

7.2 Use of Non- Acoustic Means

7.2.1 Netherlands Experience

Whilst prediction of sound power levels through non-acoustic means is an attractive possibility, it is

questionable whether in this country, sufficient relevant data exists to allow this to happen, although it

1is understood that this method is used in the Netherlands.

Rob Witte of DGMR5 has carried out some investigations of determining sound power levels by non-

acoustic means. The work consisted of investigations in the Rotterdam Harbour area of the noise

emissions of different types of existing industry. Because of Dutch legislation, a lot of detailed

acoustical data was already available. Noise data for each type of industry was then collated and

analysed, the results of which are presented in Table 6, below. The comparisons were made on the

basis of sound power per square metre (SPM).

5 Part of the Brüel & Kjær partnership in Holland


27

Type of Industry SPM,

dB(A)/m2 Standard

Deviation, dB Number of Plants Chemical plants 70 4 45 Liquids and gas storage 59 4 25 Container terminal 66 1 23 Multi purpose terminal 68 3.5 23 Shipyard 76 5 5 Container repair 70 3 18 Distribution 58 3 20 Waste processing 66 2 14 Construction 70 2 10

TABLE 6: Comparison of Sound Power per Square Metre for Various Types of Industry in Holland

For comparison, the SPM’s for three UK container ports is shown in Table 7. Although this is based

on far fewer sites than the Dutch study, there appears that there is a greater degree of variation for

these container terminals, with a larger standard deviation of around 3.5 dB.

Site Sound Power,

dB(A) Operational Area,

m2 SPM,

dB(A)/m2 Container Terminal 1 123 240000 69 Container Terminal 2 130 1040000 70 Container Terminal 3 122 700000 64 Standard Deviation 3.5

TABLE 7: Comparison of Sound Power per Square Metre for Container Terminals in UK

The type of comparison undertaken in the Netherlands could presumably be carried out in the UK.

However, there would need to be either a legal requirement for industries to supply such data, or a

voluntary effort from industry, in order to gain sufficient data.

7.2.2 Review of Industrial Process Information

As information regarding the main noise producing industries in England was gathered, any available

process information was also collated and reviewed. This was used to determine the feasibility of

using non-acoustic means to determine the source strengths of industrial noise sources. It is BVAT’s

experience that, in the UK, noise due to very similar industrial plants can vary significantly depending

on the sensitivity of the surrounding area. For the situation where an industrial plant is close to

residential properties, then the planning regime will have imposed a suitable noise limit, which may

have necessitated noise mitigation measures being incorporated into the plant design. Conversely

where an industrial plant has no sensitive receiver locations nearby, much less mitigation is likely to


28

have been required. This is one respect in which England may differ from other European countries

such as the Netherlands and Germany where industrial plants tend to be located in zones allocated

for such purposes and are, therefore, not subject to such variation in the surrounding community.

Consideration was given to including in the proposed methodology, a correction for the level of noise

mitigation included in the design, however, this would require a reasonable level of knowledge of each

industrial site which may not be sufficiently simple for the current purpose.

With regard to the use of non-acoustic means as a method for determining the noise emission of

industrial premises in England, a review has been conducted to determine if process information is

readily available for industry in this country. This review has focussed on the Environment Agency

(EA) and the Department of Trade and Industry (DTI) as sources of the required information.

The EA collates information regarding individual sites, which are within prescribed industries in the

form of an IPPC Public Register. This is held centrally and could be reviewed as a potential source of

process information. The individual applications for permits are likely to contain process information

for those sites; however, this information is not held in a central database but is held in regional EA

offices local to the sites in question. This does not therefore provide easy access to process

information for prescribed industries.

The Energy Report published by the DTI gives information on the gas throughput of oil and gas

process sites in the United Kingdom. BVAT has conducted a comparison of a number of gas

transmission sites to determine the feasibility of this method and this is reported below.

In terms of other industries, publications readily available on the DTI website were reviewed. The only

parameter generally reported was energy consumption. A number of documents were identified

which assigned energy consumption between different users i.e. domestic, industry, services and

transport.

Furthermore, documents were identified which attributed energy consumption to some individual

industries. “Energy – its impact on the environment and society” (Reference 12) identified industrial

energy consumption in terms of millions of tonnes of oil equivalent for 1999 between the following

categories:

• Chemicals;

• Metal products, machinery and equipment;

• Food, beverages and tobacco;

• Paper, printing and publishing;


29

• Other industries.

The more recent publication, “UK Energy Sector Indicators 2003 – A supplement to the Energy White

Paper, Our energy future. Creating a low carbon economy” (Reference 13) includes figures for

energy consumption in the following industries for 2001 in terms of thousands of tonnes of oil

equivalent.

• Engineering and metals;

• Iron and steel;

• Chemicals;

• Food, beverages and tobacco;

• Mineral products;

• Paper, printing and publishing;

• Textiles;

• Other industry (including construction).

Other than the Energy Report identified above, no further reference was found which attributed

energy consumption, or any other process information, to individual sites. From the sources of

information quoted in the above documents, it is considered likely that the DTI and the Office of

National Statistics hold this information. More in depth research would, however, be required to

pinpoint this further.

7.2.3 Gas Transmission Site Comparison

BVAT has conducted a significant amount of work on and around gas process sites. This has

generally involved detailed on-site noise measurements to determine the sound power levels of

individual equipment items, building a model of the site and predicting community noise levels.

Predicted community noise levels are then checked by measurement. BVAT has also developed a

model for the design of a new gas process site, which is yet to be confirmed by measurement. A

number of these sites have been selected to compare gas throughput with resultant sound power

level to give an indication as to whether such a parameter might be useful in determining the possible

sound power level of a similar site. The results of this comparison are summarised in Table 8, below.


30

Sound Power Level, dB

Site dBA 31.5 63 125 250 500 1k 2k 4k 8k

Gas

Throughput,

MMscmd*

Lw per unit

throughput

Gas Terminal A 109 117 115 110 107 105 104 102 99 95 4 103

Gas Terminal B 119 124 120 118 116 114 112 112 110 102 28 104

Gas Terminal C 127 132 134 128 123 122 121 121 117 107 26 113

Gas Terminal D 115 130 132 123 114 110 107 106 98 94 26 100

Gas Terminal E 114 133 125 121 115 112 109 104 88 86 30 99

*MMscmd = Million Standard Cubic Metres per Day

TABLE 8: Comparison of Sound Power Level per Unit Throughput for Various Gas Terminals

The calculated sound power levels per unit throughput presented in Table 8 vary by as much as

14 dB(A), with a relatively large standard deviation of 5.5 dB. Gas Terminal C contained old, and

relatively noisy gas turbine driven compressors, and this is the main reason why its normalised noise

emission is significantly greater than the other sites.

This comparison has indicated, by way of example, that there is no simple relationship between site

throughput and sound power level that could be used for this purpose. Knowledge of the type and

age of the plant would also be required to improve the relationship of the sound power level with gas

throughput. In addition, it is clear that the very distinct characteristics of the noise from some of the

sites is ignored by the use of a single figure value, but it is known that this is a very important factor in

terms of resultant disturbance (and hence annoyance) in the community. For example, Site E has a

relatively low ‘A’ weighted sound power level but has high low frequency noise content.

At present, it is not considered a viable proposition in England to use non-acoustic means to

determine noise source strengths. It is, however, possible that such a method might be developed in

due time in the light of experience gained using measurement techniques.

7.3 Modelling Concepts and Methods 7.3.1 General

As noise source strength determination through non-acoustic means is not considered a viable

proposition in this country, at least until a much greater database of industrial noise sources has been

collated, it is necessary to consider measurement techniques for this purpose.


31

As part of this research project, a fundamental decision needed to be made whether, for the purposes

of strategic noise mapping, any measurements to determine industrial plant noise source strengths

should be restricted to site boundaries or other freely accessible positions and/or involve detailed

noise measurements within the confines of an industrial site. To maintain Defra’s requirement for

developing a method that is considered to be simple, it has been assumed that detailed on-plant

measurements would not be undertaken, but that any measurements would be confined to accessible

positions outside the site. This simplified approach then needs to be investigated to see how robust it

may be for different acoustic scenarios. It must be accepted, however, that a simplified measurement

technique is not likely to capture noise character attributes, and in relation to annoyance or complaints

about industrial noise, it is known that these character attributes are of great significance.

Computer based noise modelling has been undertaken to quantify the potential errors in predicting

noise contours around industrial sites based on simplified measurement techniques to determine plant

sound power levels. The noise modelling has explored the following parameters:

• Measurement location relative to plant (distance and height);

• No of measurement locations;

• Spatial distribution of plant noise sources;

• Spectral content of plant noise;

• Topography and ground cover.

To determine the errors likely to be incurred in generating sound power levels and resulting contours

for industrial sources, based on sound pressure level measurements at plant boundaries or similar

locations, using simplified techniques, a number of scenarios have been identified which were

modelled using Cadna software. The reason for initially using a noise mapping package, as opposed

to real sites, was that the variables of propagation could be controlled. This allows for the effect of

various parameters to be analysed one at a time and, therefore, to be quantified individually. It was

therefore possible to investigate the effects of measurement height, screening, ground effects, source

types, directivity and to examine the errors introduced by model simplification.

Furthermore, this approach allowed for the methods of sound power level determination to be judged

absolutely, as opposed to relative against each other. (Sound power levels cannot be directly

measured and it is not possible, therefore, to determine the absolute error in sound power level

calculations.)


32

7.3.2 Modelling Method Assumptions

The modelling method developed was based on the basic assumption that the ISO 9613 propagation

model (as implemented by Cadna) is a realistic approximation of ‘real-world’ propagation of sound.

Although it could be argued that there are potential inaccuracies in the ISO 9613 model, this will

always be the case for any method chosen. The ISO 9613 method and Cadna software were

therefore scrutinised in detail before commencing work so that any quirks in the method / software

were understood. This meant that results could be analysed making an allowance for the modelling

method. It should therefore be possible to gain an understanding of the potential errors of

measurements and modelling methods as long as these limitations are recognised. It should be

noted, however, that the effects assessed are inherently a function of the propagation model. This will

be particularly sensitive for the cases where screening and barrier effects are encountered.

7.3.3 Modelling Method

The figure below represents graphically the modelling method utilised to assess the potential errors

due to measurement of sound power levels and the subsequent mapping of contours.

The general approach is to assume that noise modelling using assumed sound power levels for

individual sources and sound propagation characteristics to ISO 9613 is correct (Cadna modelling)

and to compute noise levels initially at hypothetical locations where in a real life situation

measurements might be made for noise source strength determination. This “measured” noise level

(actually computed using the Cadna model) is then back-calculated to a site sound power level in two

main ways:

(i) by assuming an acoustic centre for the site (including height) and using straight hemispherical

propagation over the ground (could be either hard or soft, or a mixture); and

(ii) by using a method based on ISO 8297 (Stüber method) which has a different area term in it.

The sound power levels so obtained are then re-used to give predicted noise contours around the

site at different distances. These are then compared with the noise contours obtained from the “true”

situation based on the Cadna modelling. The predictions could either be done by reverting to an

assumed point source for the industrial plant, or by assuming a distributed area source (e.g. for open

air process plant) or by “smearing” the sound power level over the walls and roof of a factory (for

“factory” type industrial sources). The modelling method is summarised in Figure 5.


33

Error

Lp Contours (True - Cadna)

s

Lw (Calculated)

Lw (True)

Actual conditions

FIGURE 5: Graphical Rep

The hypothetical industrial

until essentially modelling w

The potential errors in usin

approximation), as compar

7.3.4 Point Source

The first scenario to be m

estimate the errors likely to

upon the following paramet

Ground type (hard

Source height;

Receiver height;

Spectrum shape.

The method used was to m

microphone position. This

source (Lw calc) using a si

was then compared to the ‘

AT5414/2 Rev 1 13th October 2003

Actual condition
Lp “Measured” (True - Cadna)
Lp Contours Predicted

determination

Assumed conditions

Spreadsheet

resentation of Calculation Method

site was initially simple and was then gradually built up in its complexity

hat might be considered to be a “real” site.

g single frequency approximations to the overall sound power level (500 Hz

ed to full octave band calculations, were also investigated.

odelled was a point source. First of all, calculations were performed to

be incurred in determining the sound power level of a source, depending

ers:

/ soft);

odel a point source in Cadna, along with a receiver point representing a

‘measurement’ was then used to calculate the sound power level of the

mplified propagation method, modelled using an Excel spreadsheet. This

true’ sound power level (Lw true) of the point source.

Acoustic Technology 34

The results of these calculations are presented in Tables A7.1 to A7.5 in Appendix 7. It can be seen

from the results that:

The largest errors in determining sound power level were for either flat or rising spectrum

shapes. However, it is envisaged that this type of spectrum shape would not be commonly

encountered for industrial sites. The smallest errors were encountered for falling and typical

industrial spectrum shapes.

Errors can be minimised by increasing the measurement height (this minimises ground

effects).

The largest errors were encountered for a ‘mismatch’ of ground types, between the actual

ground type and assumed ground type. Thus, if the actual ground is soft but it is assumed to

be hard for the purposes of modelling, errors of between 4 – 7 dB(A) can be expected

(discounting effects due to screening etc).

However, using an estimate of ground effects at 500 Hz can reduce these errors. For a

typical industrial spectrum, this can reduce the error to within ±2 dB(A).

Following this initial assessment of errors in determining sound power levels, some further modelling

was carried out for point sources to determine the combined error of sound power level determination

and propagation effects at varying distances from the source, as well as quantifying the errors due to

carrying out modelling using a single figure (500 Hz propagation) model.

The method used is summarised in the Figure 6.

G=0 or G=1 calc at 100m

G=0.5

XL

G=0.5

Lw calc

Lw true Lp contours (true)

Lp meas (true)

Lp contours (calc)

FIGURE 6: Calculation Method for Point Source


35

The calculation was performed as follows:

Point Source at 2 m and 4 m height.

Measurements at 1.5 m and 4 m height

Contours at 50 m, 100 m, 250 m, 500 m, 1000 m, 2000 m

For back calculation, the distance between source and measure has been set at 50 m and

100 m.

Models use different types of spectra (falling, rising, humped and typical industrial spectrum).

Back-calculation performed in a spreadsheet for hard ground (G = 0) “Assumed Ground

Cover”, for a single frequency (500 Hz) and for full spectrum propagation.

Sound power level, Lw = Lp + Adiv + Aatm.

Contours calculated with Cadna for mixed ground (G = 0.5) “True Ground Cover”.

The results of the noise modelling are presented in summary sheets in Appendix 7.

The results of each parameter on the modelling are discussed below.

Ground Type: When modelling, it will be necessary to make assumptions about the ground type, both when

determining the sound power level of the source and when predicting contours to community

locations. It is likely that both the true and assumed ground types will be different in each case. For

example, it is likely that the ground cover in the vicinity of industrial premises will comprise mostly

hard ground (and that sound will therefore propagate hemi-spherically with minimal ground effects). It

is therefore proposed that a simplified modelling technique should assume that the ground type in the

immediate vicinity of industrial premises is hard. However, it is possible that the ground will comprise

soft ground and this will introduce errors. Obviously, the greatest error will be when the actual ground

cover is soft, where it has been assumed to be hard for the purposes of modelling. In this case, errors

of more than 3 dB(A) can be expected. However, this varies depending upon the distance between

the source and measurement point and errors of as high as 7 dB(A) can be expected in the worst

case scenario.

Source Height: Increasing the source height decreases the effect of ground effects. Therefore, the potential errors

are less for higher source heights. It is not envisaged that this effect will particularly impact the

modelling method since the source height is predetermined. However, potential errors could be

introduced by simplifying a model such that the source height is set to a value lower than it actually is.

(This may happen when noise is coming from an elevated source but the surveyor cannot determine


36

the point where the noise is coming from.) In this case, then the predicted contours could then be

underestimated. It will therefore be necessary to ensure that a reasonably accurate estimate of

source height is made in order to accurately model sound propagation over the ground. This topic is

dealt with in more detail for stacks, since this will be the extreme case where errors may occur.

Receiver Height: The modelling concentrated on two receiver heights of 1.5 m (to represent a hand held sound level

meter) and at 4 m (to represent a microphone on an extension pole as well as the receiver height

defined for noise mapping). Again, increasing the receiver height reduces the ground effects. In

general, the best correlation between “true” and predicted noise levels was when the sound pressure

measurements on which the sound power calculations were based were conducted at the same

height as the source.

Spectrum Shape: The results of the modelling show that the spectrum shape of concern has a significant effect on

propagation effects. This is to be expected since both atmospheric absorption and ground effects are

frequency dependent. The largest errors were introduced for a rising spectrum shape, with the errors

being significantly less for a typical industrial and a falling spectrum shape. However, it is not thought

that a rising spectrum shape will be encountered often for industrial noise modelling.

Overall vs. Full Octave Band Calculations: Approximating the propagation of sound to a single band model introduces errors into noise

modelling. Because propagation of sound is frequency dependent, as discussed above, the largest

errors will occur if assuming propagation for a single band (500 Hz) when the true spectrum shape is

upward sloping. The calculations show that in some cases this error may be as high as 10 dB(A).

Furthermore, this error is not particularly dependent upon either source or receiver height, since the

greatest difference in attenuation occurs at high frequencies (due to atmospheric absorption effects).

However, for the falling spectrum shape and the typical industrial spectrum shape the errors

introduced by approximating to a single band propagation model are relatively small (less than 1.5

dB(A) in most cases).

Summary of Key Findings:

The largest errors were for flat or rising spectra;

The smallest errors were for falling and typical industrial spectra;

Errors can be reduced by increasing measurement height;

Largest errors were found for mismatch of ground types;

Using an estimate of 500 Hz for ground effects reduces the potential error.


37

7.3.5 Building with Even Radiation

The purpose of this modelling scenario was to determine the errors incurred when calculating the

sound power level of a simple building, based on sound pressure measurements at various distances

back from the building façade. The building was assigned even radiation of sound per square meter

over each of its façades, including the roof. The sound power level was calculated based on the

calculated 'measurement' values assuming hemispherical radiation from the centre of the building.

The following figures show the calculation methods used. Figure 7 shows the modelling performed by

“smearing” the calculated sound power level equally over each façade, whilst Figure 8 shows how

modelling was performed by representing the sound power level as an equivalent point source. The

third scenario examined, shown in Figure 9, was representing the building as a 2-dimensional area

source, with the sound power level smeared over the area.

Lw true Lp contours (true) G=0.5

G=0 at 50,100,150m Lp meas (true)

XLLw calc Lp contours

(calc) G=0.5

FIGURE 7: Calculation Method for Building With Even Radiation – Re-Modelled by Smearing the

Calculated Sound Power Level Equally Over Each Façade

Lw true Lp contours (true) G=0.5

G=0 at 50,100,150m

G=0.5

Lp meas (true)

Lw calc XL

Lp contours (calc)

FIGURE 8: Calculation Method for Building With Even Radiation – Re-Modelled as a Point

Source


38

Lw true Lp contours

(true) G=0.5



(calc) G=0.5

FIGURE 9: Calculation Method for Building With Even Radiation – Re-Modelled as a 2D Area

Source


Measurements at 4 m height and at 50 m, 100 m, 150 m from façade


Dimensions (m): 150 x 80 x 10

10 m high building

Assume Building with Smeared Sources on each facade

Model using a Falling Spectrum

Lw’’ = 90 dBm-2 for each Façade: Roof, East, West, North, West façade

Back-calculation done for hard ground (G = 0), for 500 Hz and full spectrum

Sound power level, Lw = Lp + Adiv + Aatm

Contours calculated with Cadna for mixed ground (G = 0.5).


The results of the modelling are discussed below:

Smeared vs. Point Source Results show that smearing the derived sound power level equally over the façades and roof of the

building is generally a more accurate way of predicting contours. This is not particularly surprising

since the distribution of sound energy is being modelled as per the “real” situation. It is important to

remember that this is a “perfect” theoretical situation that would infrequently be experienced in the real

world, where it is likely that there would be a combination of point sources as well as area sources

etc. By modelling the source as a 2-dimensional area source produces smaller errors, particularly

when predicting contours closer to the source, than by modelling as a point source (typically, within

one source dimension). However, the point source method is slightly more accurate at greater


39

distances, (two source dimensions or greater). It is not as accurate as smearing the sound power

over the façades. The results therefore demonstrate that there is some benefit to be gained by

attempting to distribute sound energy in a manner as near as possible to the true situation when

carrying out modelling. In order to keep the modelling method practicable, it may be that utilising the

2-dimensional area source method is the best compromise between accuracy and simplicity.

Single vs. Octave Band Results show that the full octave band method of calculating contours generally provides a more

accurate result. The benefit of carrying out full octave band calculations is an increase in accuracy of

only around 1 – 2 dB(A) for a typical industrial spectrum.

No. of Measurement Points / Access The results show that large inaccuracies can be encountered when it is not possible to measure all

around a plant. This shows the importance of the source “directivity” in relation to the façades of the

building, as compared to an omni-directional point source. The greatest errors due to restricted

access happen when measurements are conducted close to the building. The results also show that

increasing the number of measurement points can reduce the potential for error. There may be

locations that would, alone, provide a more accurate result than multiple points, although in practice, it

would not be possible to identify these points either in the field or afterwards, unless a full comparison

and calibration of the noise maps was carried out.

Measuring Distance Results show that when measurements are performed further away from the building, representing

the building as a point source is generally just as accurate as smearing the energy over the façades.

However, this method of representing the building is not as accurate at predicting sound pressure

levels in the near-field. If the measurements are conducted close to the building then the smeared

façade method is a more accurate representation. However, the gain in accuracy is only around 1.5

dB(A) for the size of building investigated.

Building Height The results of the modelling show that the building height does not significantly affect the prediction of

sound power level or the subsequent accuracy of noise mapping, as long as a representative source

height is set.

Spectrum Shape: Again, spectrum shape significantly affects the accuracy of noise mapping, with the highest errors

being introduced for a rising spectrum shape.


40

Summary of Key Findings: The lowest error was found by smearing the derived Lw over building;

An area source is better than point source close in (i.e. less than 1 source dimension);

A point source is better at longer distances;

Full octave bands are more accurate than single frequency calculations;

Errors can be minimised by increasing the number of measurement points;

Building height is not critical in this case;

The highest errors were encountered for a rising spectrum.

7.3.6 Building with Directional Radiation (Façade)


sound power level of a building with directional sound radiation, based on sound pressure

measurements at various distances back from the building façades. The building was assigned a

radiation of sound per square metre over one of its façades. The sound power level was calculated

based on the calculated 'measurement' values assuming hemispherical radiation from the centre of

the building. The building was then re-modelled but without directivity. The purpose of doing this was

to quantify the errors introduced by simplification of the noise mapping technique so that directivity is

not taken into account. The other principal objective of this modelling scenario was to investigate how

increasing the number of measurement positions could decrease potential errors.

The following figures show the calculation methods used. Figure 10 shows the modelling performed

by “smearing” the calculated sound power level equally over each façade, whilst Figure 11 shows how

modelling was performed by representing the sound power level as an equivalent point source.

G=0.5

G=0 at 50,100,150m

G=0.5 Lw true

Lp meas (true)

Lp contours (true)

Lw calc Lp contours (calc)

XL

FIGURE 10: Calculation Method for Building With Directional Radiation – Re-Modelled by

Smearing the Calculated Sound Power Level Equally Over Each Façade


41

G=0.5 Lw true Lp contours

(true)



(calc) G=0.5

FIGURE 11: Calculation Method for Building With Directional Radiation – Re-Modelled as Point

Source


Measurement at 4 m height and at 50 m, 100 m, 150 m from façades

Contours at 50 m, 100 m, 250 m, 500 m, 1000 m, 2000 m from centre


10 m high building (has also been done at 5m)

Model using an industrial spectrum

Lw’’ = 90 dBm-2 for South Façade

Back-calculation done for hard ground (G = 0), for 500Hz

Sound Power Level, Lw = Lp + Adiv + Aatm

Contours calculated with Cadna for mixed ground (G = 0.5)


The results of the modelling are discussed below. Some degree of caution should be exercised when

analysing the results since, for this scenario, self shielding effects will be one of the biggest causes of

error. To some extent, the modelling is therefore testing the barrier calculations as per ISO 9613.

No. of Measurement Points / Access Results show that increasing the number of measurement points can reduce the potential errors due

to directivity, particularly over greater distances. However, without accounting for directivity in the

modelling, the errors are arguably too great in each individual direction to be considered robust. The

greatest errors are encountered when no measurements are made in the direction of the radiating

façade, or in the opposite direction. This reinforces the need for as many measurements as possible

to be carried out, in as many directions as possible.


42

Smeared vs. Point Source Results show that the potential maximum errors are higher when representing the source as a point

source. However, the point source method is more accurate in certain directions, particularly where

measurements have been conducted at greater distances from the building. Neither method of

representing the source can be considered as accurate without accounting for directivity.

Measuring Distance In general, the magnitude of errors decreased for greater measurement distances. This was the case

for a range of contour prediction distances. However, the errors encountered were arguably still too

great to be considered an accurate method of modelling.

If the actual source has directivity and this is not identified from the measurements, then large errors

can be expected when carrying out noise mapping. The potential errors are greatest when access is

only available for either the noise radiating face, or in the opposite direction. In the specific cases

examined, these errors were as much as 24 dB(A). This degree of error is assumed unacceptable in

terms of noise mapping. Therefore, in order to minimise potential errors in noise mapping, the

method of determining and distributing the sound power level of the source will need to take into

account directivity.

Summary of Key Findings: Self-screening (barrier) effects become important, relying on ISO 9613;

A greater number of measurement points reduces the error;

Errors can be minimised by accounting for directivity;

A point source model is better in certain directions (but still requires directivity);

Increasing the measuring distance reduces the error.

7.3.7 Building with Directional Radiation (Façade Between Two Buildings)


sound power level of a building with directional sound radiation and screened by another building,

based on sound pressure measurements at various distances back from the façade of the relevant

building. The source building was assigned a radiation of sound per square metre over one of its

façades, facing another (reflecting) building. The sound power level was calculated based on the

calculated 'measurement' values assuming hemispherical radiation from the centre of the two

buildings. The building was then re-modelled but without directivity. The purpose of doing this was to

quantify the errors introduced by simplification of the noise mapping technique so that directivity is not

taken into account for more complex scenarios. The other principal objective of this modelling


43

scenario was to investigate how increasing the number of measurement positions would affect

potential errors. Figure 12 shows the calculation method used.

XL

Lw true

G=0 at 50,100,150m

G=0.5

G=0.5

Lw calc

Lp contours (true)

Lp meas (true)

Lp contours (calc)

FIGURE 12: Calculation Method for 2 Buildings With Directional Radiation – Re-Modelled by



10 m high buildings

10 m gap between the two buildings



Brick absorption coefficient α = 0.05

Max. order of reflection = 5

Back-calculation done for hard ground (G=0), for 500Hz

Lw = Lp + Adiv + Aatm

Contours are calculated with Cadna for a mixed ground (G =0.5) with barrier effect

Measurement at 4 m height and at 50 m, 100 m, 150 m






44

No. of Measurement Points / Access The results show that large errors can be expected if no account is taken of directivity. The error is

largest where results from one direction have been used to predict contours in another direction. In

some cases, these errors were as high as 26 dB(A). Again, increasing the number of measurement

points reduces the potential for error, although this may conversely increase the error in certain axes.

Measuring Distance The relationship between measurement distance and error is rather complex for this scenario. The

results show that, whilst increasing the measurement distance may improve accuracy in one axis, this

would have a detrimental effect on the other axes. Furthermore, the magnitude of the error also

depends upon the distance to which the contours are plotted.

Results show that any modelling method developed must include provision for directivity of sources if

it is to be reasonably accurate. This implies a need for measurements on all sides of an industrial site

(always, assuming of course, that there are noise sensitive locations on all sides of the site).

Summary of Key Findings: Large errors are encountered if no account is taken of directivity;

Increasing the number of measurement points reduces the potential error;

The relationship between the number of measurement points and distance is complex;

Directivity expressions are necessary to minimise errors.

7.3.8 Building with Directional Radiation (Façade Between Four Buildings)

The purpose of this modelling scenario was to develop the scenarios examined above, but for a more

complex case of a single source façade between four buildings. The purpose of doing this was to

quantify the errors for an increasingly complex scenario and to investigate whether multiple reflections

more likely to be experienced in real life would reduce errors due to screening etc. Figure 13 shows

the calculation method used.


45

G=0.5 Lw true Lp contours (true)



(calc) G=0.5

FIGURE 13: Calculation Method for 4 Buildings With Directional Radiation – Re-Modelled by



10 m high buildings

10 m gap between the four buildings





Back-calculation done for hard ground (G = 0), for 500Hz


Contours are calculated with Cadna for a mixed ground (G = 0.5) with barrier effect

Measurement at 4m height and at 50 m, 100 m, 150 m





No. of Measurement Points / Access The results show that large errors can be expected if no account is taken of directivity. Again, the

error is largest where results from one direction have been used to predict contours in another

direction. However, the magnitude of the potential errors is greatly reduced in comparison to a source

between two buildings, due to on-site reflections etc. However, the errors would still be unacceptable

for noise mapping unless directivity was taken into account.


46

Measuring Distance The relationship between measurement distance and error is, again, rather complex for this scenario.

The general trend is that errors are slightly smaller for greater measurement distances. However, the

degree of error again depends on not only measurement distance, but the distance to which sound

pressure levels are to be predicted.

Results show that increasing the complexity of the source, particularly by introducing multiple

reflecting surfaces, reduces the effects of on-plant screening. This reduces the potential errors likely

to be incurred when modelling the site by a simplified methodology. However, the potential errors are

arguably still too high for modelling without accounting for directivity in some way.

Summary of Key Findings: Large errors are encountered if no account is taken of directivity;

The error can be smaller due to on-site reflections;

Errors are slightly smaller for greater measurement distances;

Greater in-plant reflections reduce the error, but directivity information is still required. 7.3.9 Point Source with Building Providing Screening

The purpose of this modelling scenario was to determine the errors incurred when representing a

point source between buildings by smearing the sound power level over the building façades. The

sound power level was back-calculated based on the calculated 'measurement' values assuming

hemispherical radiation from the centre of the buildings (actual source location in this case). The

building was then re-modelled without directivity. The purpose of doing this was to quantify the errors

introduced by simplification of the noise mapping technique where it is not known what type of source

is to be represented, as well as to quantify errors due to screening effects. Figure 14 shows the

calculation method used.


47

XLLw calc

Lw true

G=0

at 50,100,150m

G=0.5

G=0.5

Lp contours (true)

Lp meas (true)

Lp contours (calc)

FIGURE 14: Calculation Method for Point Source Between 2 Buildings – Re-Modelled by



10 m high buildings

10 m gap between the two buildings

Point Source at 5 m high between two buildings


Lw = 90 dB for the point source



Back-calculation done for hard ground (G = 0), for 500Hz and full spectrum


Contours are calculated with Cadna for mixed ground (G = 0.5) with barrier effect

Measurement at 4m height and at 50 m, 100 m, 150 m





No. of Measurement Points / Access The results show that large errors can be expected if no account is taken of directivity. The error is

largest where results from one direction have been used to predict contours in another direction. The

potential error is reduced for a greater number of measurement points, although the error in each

direction would arguably still be too great for noise mapping purposes. Although the error would

reduce for more complex sites, it would arguably still be too great in magnitude for such a


48

simplification to be acceptable. This therefore re-iterates the need for directivity to be accounted for in

the proposed method.

Measuring Distance The results show that, for this scenario, measurement distance does not significantly affect the

potential errors incurred.

Single Band vs. Octave Calculations The results show that, in this particular scenario, there is no significant advantage of using octave full

octave band calculations rather than single figure calculations.

Summary of Key Findings: Large errors are encountered if directivity is not taken into account;

The error can be reduced by increased the number of measurement points;

The measurement distance is not significant;

No significant benefit is achieved by using full octave band instead of single frequency

calculations (for industrial spectrum).

7.3.10 Elevated Sources (Point Source on Roof)

The purpose of this modelling scenario was to determine the errors incurred when representing a

point source on the roof of a building by smearing the sound power level over the building façades.

The sound power level was back-calculated based on the calculated 'measurement' values assuming

hemispherical radiation from the centre of the building. The building was then re-modelled without

directivity. The purpose of doing this was to quantify the errors introduced by simplification of the

noise mapping technique where it is not known what type of source is to be represented, as well as to

quantify errors due to screening effects. Figure 15 shows the calculation method used.


49

XLLw calc

Lw true

G=0 at 50,100,150m (4m and 1.5m)

G=0.5

G=0.5

Lp contours (true)

Lp meas (true)

Lp contours (calc)

FIGURE 15: Calculation Method for Point Source on the Roof of a Building – Re-Modelled by




10 m high buildings

Model using a falling spectrum


Back-calculation done for hard ground (G = 0), for 500Hz and full spectrum


Contours are calculated with Cadna for a mixed ground (G = 0.5) with barrier effect

Measurements at 4 m and 1.5 m height and 50 m,100 m,150 m




Effect of Measurement Height The actual relationship between measurement height and errors is rather complex, depending upon

not only the type of calculation performed, but also on the distance to which the contours are

calculated and the side of the building on which measurements were taken. In general, the results

show that the errors incurred can be reduced in this scenario by increasing measurement height when

the sound power is determined using full octave band calculations. However, the opposite is true if

single-figure calculations are used. In any case, there appears to be no significant advantage in using

higher measurements for this particular scenario. Nevertheless, some degree of caution must be

used since the ISO 9613 calculation procedure uses a barrier calculation which results in a 5 dB

barrier effect as long as the observation point is below the line of sight of the barrier. Therefore, for a


50

10 m building and for contour plots at 4 m, there will always be a self screening (barrier) effect no

matter how far away from the building. Whether this would happen in the real world is debateable due

not only to refraction, but also to reflections from other buildings etc.

Single Band vs. Octave Calculations The results show that, in this particular scenario, there is no advantage of using octave full octave

band calculations rather than single figure calculations. Indeed, the 500 Hz propagation appears to

represent the true scenario in this case more accurately. This is perhaps due to the reduction in self

screening effects at 500 Hz as opposed to higher frequencies.

Measuring Distance The errors incurred are reduced by measuring further away from the building. This is because the

magnitude of the self screening (barrier) effect reduces with distance. As discussed above, this would

be even more pronounced in the real world.

Summary of Key Findings: Potential errors can be reduced by increasing measurement height for full octave calculations;

The opposite effect was found for single frequency calculations;

These errors are possibly due to barrier effects (ISO barrier model used in calculation);

The potential error can be reduced by measuring further from the building.

7.3.11 Elevated Sources (Stacks)

The purpose of this modelling scenario was to determine the errors incurred when representing a tall

stack by a point source nearer to the ground. The sound power level was back-calculated based on

the calculated 'measurement' values assuming hemispherical radiation from the stack, which was

then re-modelled based on an assumed height. The purpose of doing this was to quantify the errors

introduced by simplification of the noise mapping technique where it is not known where the noise

source is located (i.e. whether noise is coming from an elevated source or a ground level source).

Figure 16 shows the calculation method used.


51

Lw true Lp contours (true) G=0.5 Top

G=0 Top at 50,100,150m

G=0.5 4m

Lp meas (true)

Lw calc XL

Lp contours (calc)

FIGURE 16: Calculation Method for Elevated Point Source – Re-Modelled by Assuming Point

Source at Lower Height


Models using industrial spectrum

Lw = 90 dB

Back-calculation done for hard ground (G = 0), for 500 Hz and full spectrum

Contours calculated with Cadna for mixed ground (G = 0.5)

Measurements at 4 m height and at 50 m, 100 m, 150 m


The stack directivity was set using the automatic configuration provided in Cadna. This assigns

vertical directivity to the stack exit, based on German standards (Reference 14). The parameters

included are source height, distance from receiver to source, downwind speed, temperature and exit

speed of the emission medium, and the ambient temperature.

The results of the noise modelling are presented in summary sheets in Appendix 14 and are

discussed below:

Effect of Source Height A larger source height generally gives rise to greater errors, particularly when predicting contours

further back from the stack from measurements made closer to the stack. This is because stacks are

very directional, depending upon the angle to the vertical axis. Increasing the stack height, whilst

maintaining the measuring distance, effectively increases the angle to the vertical, and therefore

increases the errors due to directivity. Furthermore, there is also a difference between ground effects

at, source heights of say 100 m and 4 m. This means that, even without any error incurred in

measuring the sound power of the stack exit, errors will be introduced by representing the source at

the incorrect height.


52

Single Band vs. Octave Calculations The results show that the full octave band calculations are slightly more accurate than the single band

calculations. However, the difference between the two methods is only around 1 or 2 dB(A) at the

most, compared with total errors of up to 14 dB(A). It is not, therefore, considered that this increase in

accuracy is significant.

Measuring Distance The incurred errors are reduced by measuring further away from the stack. This is due to a

combination of two factors: directivity and reduced error in the estimated distance to the source.

Stacks are highly directional, particularly in the vertical axis, with a greater proportion of the sound

energy being directed upwards (this is frequency dependent). Therefore, measurements made

directly under a stack will underestimate the sound power level by a large amount. For example,

measurements conducted under a stack, at an angle of 120o from the vertical axis, could

underestimate the sound power of the stack exit by between 10 and 20 dB(A), depending upon

frequency content. It is possible to correct for this, but only with a detailed knowledge of the stack

characteristics, such as exhaust gas velocity and temperature, stack exit diameter, wind speed at the

tip etc. and it is unlikely that these parameters would be available.

Without gaining access to the site and carrying out very detailed measurements (probably going up to

the stack exit in a crane basket or “cherry picker”) it is unlikely that noise from a stack could be

separated from noise from the rest of the site. Furthermore, it is likely that stack noise could be the

significant source at distances further away from the site, due to the stack directivity, and reduced

ground effects and small air absorption due to the assumed low frequency nature of the stack noise.

(Note: some stacks may also emit mid to high frequency noise).

Summary of Key Findings: Greater errors are found with increasing the height of the stack;

The errors are due to change in directivity and ground effects;

There is no significant benefit in using full octaves (for industrial spectrum);

The error is reduced by measuring further from stack.

7.3.12 Extended Sources

Some investigation has been carried out into the potential errors that could be incurred when

determining the sound power level of extended sources. When representing an extended source as a

series of point sources, it is important that the sound power level of each point can be determined


53

independently of the adjoining points. This means that the influence of adjacent sources must be fully

understood in order to both measure and model noise in this manner.

For an extended source comprising of n elements (represented by a point source in the centre of each

element:

n = nth element or source

Lw,n = sound power level of each source centre

Lp,n = sound pressure level at measurement point opposite point source n.

r = distance between measurement point and source

This is shown in Figure 17, below.

22 rx + 222)1( rxn +−α

Lpn Lp2 Lp1

r

x

Lwn Lw2 Lw1

x

r

FIGURE 17: Relationship Between Adjacent Sources Showing Influence on Lw Determination

( ){ }[ ]

= ∑

=

+−−n

n

rxnLwp

nL1

12log10 2210log10 π

In order to calculate the effects of adjacent sources, then it is necessary to simplify the situation such

that Lw1 = Lw2 = Lwn. Therefore, if ∆Lp = 10 then there will only be a small contribution (0.5 dB) from

Lw2 to the sound pressure level Lp1.


54

Then

2

22log1010

rrxLp

+==∆

°=∴ 72α

rx 3=⇒

Therefore, in order for an adjacent element to have a small impact on the measurement position then

the angle subtended, α must be at least 72o.

Figure 18 extends this concept to consider up to 10 sources in each direction, thus calculating the

cumulative effect for large extended sources. This would, in principle, allow a correction to be made

to any measurements in order to assign a sound power level to an element. It should be noted that

when the calculation is extended to several points on each side, then the calculated error at α = 72o

(i.e. an angle of view between elements of 144o) increases to 1.2 dB(A)

0

2

4

6

8

10

12

14

0 45 90 135 180Angle of View (n-1 to n+1)

Erro

r, dB

FIGURE 18: Calculated Error for Measurement of Sound Power Level of Extended Sources as a Relationship of Angle Subtended Between Adjacent Sources


55

Worked Example:

Lw 1 Lw 2 Lw 3

130o

Lp

Lw 1 Lw 2 Lw 3Lw 1 Lw 2 Lw 3Lw 1 Lw 2 Lw 3

130o130o

LpLp

FIGURE 19: Worked Example – Extended Source

In this case, the purpose of taking a measurement at the position shown, is to attribute a sound power

to the middle segment, Lw 2, and this gives a value of, say, 100 dB(A). However, segments 1 and 3

will contribute to the measured sound pressure level and the calculated sound power level will

therefore be too high. It is possible to estimate the error introduced due to the adjacent elements by

applying a correction, using Figure 18, above (assuming the adjacent elements have a similar sound

power level). For the angle shown (130o), the error is approximately 2 dB(A). This can then be

subtracted from the value for the calculated sound power level to give a corrected value of 98 dB(A).

The use of this type of correction factor is relevant to large extended sources where there could be a

requirement to relate measured sound pressure levels at boundary points, or other positions, to

particular areas of the site and to model each of these areas as a “small” source to determine partial

sound power levels for the different areas of the site. In principle, and according to Reference 5, a

source can be considered as “small” when the measurement distance from the centre of the source is

at least twice the characteristic source dimension. This is a function of the dimensions of the site and

the height of the noise sources, but for a rectangular site where one side is twice the length of the

other and the dimensions are large compared with the source height, then the characteristic

dimension is 1.1 x site width. Thus noise measurements would need to be made at a minimum

distance of 2.2 x site width from the centre of that part of the site to allow that element to be

considered as a small source.

Conversely, knowing the distance of the noise measurement from the centre of the site, and the width

of the site, enables a calculation to be made of the approximate length of the site that would then form

an area which would be considered to be small in relation to that measurement position, (for the

purposes of calculating the sound power level of that element of the site). Having divided up the site

in this fashion then correction factors can be calculated for individual measurement positions,

although this relies on the assumption of uniformity of sound power level density over the site area.


56

Summary of Key Findings: It is possible to represent an extended source as sequence of point sources;

The error can be minimised by considering the angle of view to adjacent elements;

Use elements of site which are considered “small” in relation to measurement distance.

7.3.13 Combination of Several Source / Screening Concepts

The purpose of this modelling scenario was to investigate the errors incurred when calculating the

sound power level of a complex industrial site, based on different methods of determining sound

power and of modelling the site. The two methods investigated for sound power level determination

were:

i. BS ISO 8297 Method (i.e. Stüber method) – see Section 3.4;

ii. Hemi-spherical Propagation Method (Based on ISO 9613).

Each of these was calculated for both single band and full octave methods.

The resultant sound power levels were then distributed in two ways: as a point source and as a 2-

dimensional area source.

The purpose of this exercise was to investigate the potential errors in both determining sound power

levels and for calculating noise contours at a more complex “generic” industrial site. This way, the

errors should combine in a rather more realistic way than the theoretical “extreme” cases examined

above and allow a more pragmatic approach to developing a noise mapping method to be developed.

The calculations are summarised in the following figures. Figure 20 shows the modelling performed

by representing the sound power level as a 2D area source, whilst Figure 21 shows how modelling

was performed by representing the sound power level as an equivalent point source


57

XLLp contours (calc)

Lp contours (true)

Lp meas (true)

Lw calc

Lw true

G=0 at 500,1000,2000m

G=0.5

G=0.5

FIGURE 20: Calculation Method for Combination of Several Source / Screening Concepts – Re-Modelled as a 2D Area Source

G=0.5

G=0.5 Lp contours (true)

Lp meas (true)

G=0 at 500,1000,2000m

Lw true

Lw calc XL

Lp contours (calc)

FIGURE 21: Calculation Method for Combination of Several Source / Screening Concepts –

Re-Modelled as a Point Source

The site has been “constructed” using a combination of several different scenarios, including elevated

point sources, directional sources, façade sources, screening effects etc. Furthermore, the site has

been surrounded on three sides by reflective buildings (with 50 % acoustic transparency). The site

ground has been set as hard, whilst the remainder of ground has been set as 50% hard / 50% soft.

The dimensions of buildings etc were based on real site maps and represent a typical layout that

could be expected for a factory complex in a mixed residential / industrial area. Various spectrum

shapes were used in the model, based on the types of source likely to be encountered in typical


58

industry. The model does not try to recreate an existing site but, rather, is an attempt to set up a

generic industrial source. A representation of the site layout is shown in Figure 22, below:

FIGURE 22: Graphical Representation of Site Layout for Combination of Several Source /

Screening Concepts



Stüber vs. Hemispherical The results show that the Stüber method is more accurate at predicting the sound power level of the

site than the distant hemi-spherical method. This is because of the screening encountered between

distant measurement positions and the site. Indeed, it is very likely that this type of situation will arise

in built up areas and it will therefore be very important to take measurements with direct line of sight to

the site. However, it is apparent that the Stüber method is an accurate method of measuring the

sound power level of a site and would therefore be recommended over the hemi-spherical method

where access is available.

2D Area vs. Point Source Results show that representing the site as a 2 dimensional area source is more accurate than the

point source method when the Stüber method has been used to determine the sound power level.

The relationship between the methods is, however, rather more complex for the hemispherical sound

power determination results. The point source method is very accurate at predicting noise levels at

the same distance back from the site as the sound power measurements were conducted. However,

this error generally increases at other ranges.


59

Full Octave vs. Single Band Results show that the full octave calculations are generally about 1 dB(A) more accurate than the

single band calculations.

Summary of Key Findings: A generic industrial site has been modelled;

The Stüber method is better for determining LW than the distant hemispherical method;

The error can be reduced by representing the site as an area rather than point source;

Full octave band calculations are only 1 dB(A) more accurate than single frequency calculations.

7.3.14 Modelling of Real (Open) Site

Following on from the modelling carried out above, some additional modelling work has been carried

out based on a noise model of a real industrial site (an oil gathering station). Hence the site layout,

sound power levels of equipment, directivities etc. are all based on a real world situation, albeit

modelled. The site differs from the one modelled previously by being even more complex as well as

being an open plan site, rather than a factory.

The same modelling concepts were investigated as the theoretical generic site above. Because the

model has been calibrated and validated by surveys at community locations, there is some degree of

confidence in the results of the “true” model.

Figure 23, below, shows a 3D view of the site model.

FIGURE 23: Graphical Representation of Oil Gathering Station Cadna Model


60

The results of the noise modelling are presented in summary sheets in Appendix 16, and are

discussed below:

Stüber vs. Hemispherical The results show that the Stüber method is more accurate at predicting the sound power level of the

plant than the hemispherical method. Because the errors for the hemispherical method reduced when

modelled over flat land and with the bund removed (as opposed to the true land profile), it is thought

that the errors are largely due to ground effects and attenuation due to the bund surrounding the site.

Further modelling (setting the ground in the model to be hard) showed that the errors are largely due

to ground effects, accounting for around 5 dB(A) of the total error. This shows that it will not be

possible to dismiss ground effects over soft ground when determining the sound power level of plants,

based on measurements from further afield.

In order to gain an understanding of the magnitude of ground effects when calculating the sound

power level by the hemispherical method, the difference in levels for hard and soft ground was

computed. This effect is plotted in the Figure 24, below.

0

1

2

3

4

5

6

7

8

10 100 1000 10000Distance, m

Diff

eren

ce b

etw

een

G=0

and

G=1

, dB

FIGURE 24: Difference in Calculated Sound Pressure Level Between Hard and Soft Ground Calculations For Oil Gathering Station Model (Receiver Height 4m)

The figure shows that the difference in levels increases from 1 dB(A) at 50 m and steadies off at

around 8 dB(A) at 5km.


61

2D Area vs. Point Source The relationship between the errors incurred and the distribution of the sound source is rather

complex and also depends on the method used to determine the power level in the first place. For the

Stüber method, representing the source as a 2D area source appears to be slightly more accurate,

particularly nearer to the site. However, the actual difference in errors is not significant. For the

hemispherical method, the difference in errors between distributing the sound power as a point source

and as a 2D area source is, again, not significant. In particular, the two methods calculate almost

identical sound pressure levels at larger distances from the source (greater than 1 km).

8. SITE INVESTIGATIONS

8.1 General

The theoretical modelling work started from very simple concepts and gradually built up in complexity

until representing a situation likely to be encountered in real life. The next logical step was to take this

one step further, and to carry out measurements on real sites. This would introduce further variables

that cannot be controlled, such as background noise, meteorological conditions and real access

restrictions. However, since these are the parameters that will affect the results when the mapping

method is put into practice, it is important to appreciate these effects.

As part of this research project, it was agreed with Defra that noise measurements were to be

undertaken at two industrial sites. This had the following objectives:

To test the logic and robustness of determining sound power levels and subsequent contour

predictions;

To further determine the potential errors inherent in the modelling methods;

To appreciate the practicalities of undertaking noise measurements for the purpose of

strategic noise mapping.

The sites were chosen such that one site represented a typical factory unit, with a significant portion

of it as a building structure, situated in a mainly residential area. The second site was chosen to be

an open industrial noise source with dominant sound pressure levels at the plant boundary, and

where plant boundary measurements could be made. This site was also the one modelled in Section

7.3.14, above, allowing comparison of the data with sound power levels measured using a sound

intensity technique.


62

8.2 Factory Unit Tests

8.2.1 Method

The instrumentation comprised of a Brüel & Kjær integrating sound level meter, type 2260. The meter

was fitted with a Brüel & Kjær type 4189 ½ inch microphone, connected via an extension lead. The

microphone was then attached to the end of a telescopic pole so that measurements could be

conducted at the desired height. A record was made of overall A-weighted and linear octave band

Leq, L90, and Lmax noise indices.

Two sets of measurements were taken, as follows:

a) Boundary noise measurements were conducted at a height of 5 m above grade. Measurements

were conducted after midnight in order to minimise disturbance from other noise sources.

Because noise from the site was steady, measurements were generally kept to approximately 30

seconds (or when the displayed sound level levelled out). This meant that measurements could

be conducted in between events such as passing cars or aircraft. Any extraneous events not

connected with the factory operation were paused out from the sample.

b) Community noise measurements were conducted at a height of 4 m above grade. The

measurements utilised the same equipment and basic method as described for the boundary

noise measurements (for pragmatic reasons the community measurement duration was kept to

approximately 30 seconds at each site. In general a longer sampling period would normally be

appropriate). These measurements commenced after 2 am to minimise background noise from

other traffic etc, due to the reduced impact of site noise on the ambient noise environment. Any

local events not connected with the factory operation were paused out from the sample.

During the tests, a note was made of prevailing weather conditions, including temperature, wind

speed and direction and cloud cover. A note was made of any sounds contributing to the measured

level along with the surveyor’s subjective comments.

The boundary measurements were conducted at the nearest publicly accessible location to the site

boundary and marked on a map. From this, it was possible to determine the distance to the plant (in

metres) by measuring the distances on the map following the survey. The measurement locations are

presented in the Figure 25.


63

SITE SITE

F F

E E DD

1010

8 8 99

11111212

13131 1 2 2

3 3 4 4 5 5

7 7 6 6

AA

BB

CC

1

A

Key: Plant area, Sp Measurement Area, Sm Community Location Boundary Location

FIGURE 25: Community and Boundary Measurement Locations – Factory Unit Tests

It can be seen that there was no direct access to the southern site boundary and therefore no

measurements were conducted here. A much larger industrial area, consisting of a container port,

docks and other industrial premises, is located directly to the south of a main road which runs close to

the site. This industrial area, along with the main road, are also significant sources of noise.

8.2.2 Analysis of Results

The measured sound pressure levels at the site boundary were used to calculate the plant’s sound

power level, based on the Stüber method, utilising both the overall (500 Hz single band) method as

well as a full octave band calculation.

First of all, the average sound pressure level for the boundary measurements was calculated. No

correction was made for background noise, as noise from the site was deemed to be dominant.

(Noise levels of between 40 and 50 dB(A) were recorded, compared with an estimated residual noise

of around 30 dB(A) or less.)

The calculations used the measured L90 values in order to distinguish the steady noise from the

factory from other time varying noise. However, a correction of 1 dB was made to the measured

levels to effectively convert from L90 to Leq.

The measurement area and plant area were worked out based on a scale map of the area, rather

than measurements on site. These were as follows:


64

Measurement area, Sm = 121142 m2

Measurement contour length, l = 1481 m

Plant area, Sp = 77105 m2

Mean height, h = 10 m (based on estimate whilst on site, by observation, of the mean height of the

noise sources)

The results of the calculations are presented in Table 9.

Calculation Method Sound Power level, dB(A)

Octave Band 97.1

Single Band 97.7

TABLE 9: Comparison of Sound Power Level Determination for Full Octave and Single Band Calculations for Factory Unit Tests

It can be seen from Table 9 that there is a very good correlation between the single band and full

octave calculations.

The sound power levels calculated above were entered into a simple 2D model of the area using

Cadna software, in order to provide a comparison between calculated and measured sound pressure

levels at community locations. The results of this analysis are presented in Table 10.

Sound Pressure Level, dB(A) Method A B C D E F

Octave Band 27.0 30.7 29.3 31.0 29.4 26.1 Single Band 27.9 31.7 30.3 32.0 30.7 27.2 Actual Measured Lp 34.6 33.8 35.0 32.3 35.3 38.5 Estimated Residual Level 30 30 30 30 30 30 Corrected Measured Level 32.8 31.5 33.3 28.4 33.8 37.8 TABLE 10: Comparison of Calculated Sound Pressure Levels With Measured Values for Factory

Unit Tests Because residual noise levels, in general, were estimated to be just under 30 dB(A), the measured

sound pressure levels at most of the community locations are very close to the predicted ones. It

should be noted that the site was not audible at Locations E and F, where noise levels were

subjectively dominated by distant traffic and residual noise levels would have been higher.


65

8.3 Open-Site Source Tests

8.3.1 Method

The instrumentation comprised of a Brüel & Kjær integrating sound level meter, type 2260. The meter

was fitted with a Brüel & Kjær type 4189 ½ inch microphone, connected via an extension lead. The

microphone was then attached to the end of a telescopic fishing rod so that measurements could be

conducted at the desired height. A record was made of overall A-weighted and linear octave band

Leq, L90, and Lmax noise indices.

Two sets of measurements were taken, as follows:

a) Boundary noise measurements were conducted at a height of 5 m above grade. Measurements

were conducted in the late evening in order to minimise disturbance from other noise sources.

Because noise from the site was steady, measurements were generally kept to approximately 30

seconds (or when the displayed sound level levelled out). This meant that measurements could

be conducted in between events such as gusts of wind in the trees etc. Any extraneous events

not connected with the site operation were paused out from the sample.

b) Further noise measurements were conducted at a further distance back from the site at a height

of 5 m above grade. The measurements utilised the same equipment and basic method as

described for the boundary noise measurements. Any local events not connected with the factory

operation were paused out from the sample.

During the tests, a note was made of prevailing weather conditions, including temperature, wind

speed and direction and cloud cover. A note was made of any sounds contributing to the measured

level along with the surveyor’s subjective comments.

All boundary measurements were conducted at 1 m from the boundary fence. The far-field

measurement locations were noted on a map and the distance to the centre of the site was worked

out following the survey. The measurement locations are presented in the Figure 26.


66

South Far-field Measurement

North Far-field Measurement

FIGURE 26: Measurement Positions – Open Site Tests

Because of weather conditions, no measurements were conducted at community locations.

8.2.2 Analysis of Results

The measured Leq sound pressure levels at the site boundary were used to calculate the plant’s sound

power level, based on the Stüber method. In addition, the distant measurements to the north and

south were also used to calculate the sound power level for comparison. For each method,

calculations were performed utilising both the overall (500 Hz single band) method as well as a full

octave band calculation. The hemispherical method of calculating sound power included a correction

for ground effects since the terrain between the site and measurement position was soft. This was

based on the values presented in ISO 9613 for soft ground, using an Excel spreadsheet for the

calculation.

The measurement area, plant area and other relevant distances etc. were worked out based on a

scale map of the area, rather than measurements on site. These were as follows:

Measurement area, Sm = 23000 m2

Measurement contour length, l = 620 m

Plant area, Sp = 19780m2

Mean height, h = 5 m (based on estimate whilst on site, by observation)


67

Distance from centre of site to northern far-field measurement point = 260 m

Distance from centre of site to southern far-field measurement point = 320 m

The results of the calculations are presented in Table 11.

Sound Power level, dB(A) Calculation Method Octave Band Single Band

Stüber Method 105.4 104.1

Hemispherical Calculation (From North) 105.3 105.4

Hemispherical Calculation (From South) 105.8 105.8

Small Source Method (Intensity)6 103.9 -

TABLE 11: Comparison of Calculated Sound Power Level for Different Methods of Determination – Open Site Tests

It can be seen from Table 11 that there is a very good correlation between the methods for sound

power level determination. In particular, it can be seen that the difference between the full octave

band calculations and the single band simplified calculations is negligible. Although all three methods

yield a slightly higher result from the intensity (small source) method, this is not necessarily due to

survey technique as the survey was conducted on a different day.

The sound power levels calculated above were entered into a 2D model of the area using Cadna

software, in order to provide a comparison between calculated and measured sound pressure levels

at the more distant locations. The results of this analysis are presented in Tables 12 and 13.

Sound Pressure Level, dB(A) Method 260 m North 320 m South

Stüber 40.6 39.6 Hemisphere North 41.6 40.6 Hemisphere South 42.6 41.6

Oct

ave

Band

Actual Measured SPL 41.5 39.9

TABLE 12: Comparison of Calculated Sound Pressure Levels With Measured Values Using Full Octave Band Calculations - Open Site Tests

6 The measurements to determine this value were made on a different day to the plant boundary and more distant measurements


68

Sound Pressure Level, dB(A) Method 260 m North 320 m South

Stüber 42.4 41.5 Hemisphere North 43.6 42.7 Hemisphere South 43.7 42.8

Sing

le B

and

Actual Measured SPL 41.5 39.9

TABLE 13: Comparison of Calculated Sound Pressure Levels With Measured Values Using Single Band Calculations - Open Site Tests

It can be seen that the model offers good correlation with actual measured levels for all of the

methods used.

9. RECOMMENDED METHODOLOGY FOR SOURCE NOISE LEVEL DETERMINATION

9.1 Scope

The purpose of this section is to present a methodology for representing industrial noise sources as

part of the first phase of noise mapping (as defined in the National Ambient Noise Strategy and

required by Directive 2002/49/EC). The development of a standardised approach on how to map

sources of industrial noise is critical to determining the ambient noise levels as the UK has no national

standard. The presented method has been developed to provide consistent and reasonably accurate

representation of industrial noise sources for noise mapping and will provide the necessary firm basis

for assessing the effects of industrial noise and mitigation where this is considered necessary.

The method is a compromise between obtaining an adequate level of detail and accuracy, and

making the method suitably simple in terms of use and output. It should therefore be noted that,

whilst the method presented allows a reasonably robust determination of ambient noise levels for the

purposes of the first phase of noise mapping, this does not replace more detailed measurements or

modelling that may be required under planning conditions or IPPC applications etc. Furthermore, it

must be remembered that this method is intended to assist in undertaking strategic noise mapping. It

will almost certainly be necessary to make a more detailed assessment of plant noise levels in order

to investigate a specific noise issue.


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9.2 Principle of Modelling Method

9.2.1 Determination of Sound Power Level

The presented method is based upon determination of sound power levels based upon

measurements of sound pressure level at discrete points in the vicinity of, but not actually on, the

industrial premises.

Consideration has been given to ensuring easy access to measurement locations and it has therefore

been assumed that this will exclude entry into the industrial site itself. The method has, therefore,

been developed based on the assumption that measurements will need to be made at publicly

accessible points close to the industrial premises concerned.

It is anticipated that the available access points to different sites will vary widely. Some sites will have

access points all around the boundary fence, whereas some sites will only have publicly accessible

points at some distance from the site. The proposed measurement method has therefore been

developed to allow a flexible approach to determining the sound power level of industrial sites.

9.2.2 Modelling of Industrial Plant Noise

It is recognised that a flexibility of approach should be allowed in terms of assigning and distributing

the sound power level of the sources, once determined by measurement. In principle, the most

accurate method of representing an industrial site would be to distribute the sound power in a way as

close as possible to the original situation (i.e. the physical distribution actually encountered).

However, this will not always be practical because, not only will the true situation often be rather

complex, but it will not always be possible to determine the distribution of sources based on

observations from publicly accessible locations.

The computer modelling carried out for this project demonstrated that correctly identifying the

directivity of the source must play a significant role in distributing the sound power levels on site. For

this reason, it is proposed that the noise mapping method includes a procedure to both calculate

directivity and then to apportion this characteristic to the subsequent computer model, if at all

possible.

Following on from this, the modelling showed that it is important that the site be represented

accurately in terms of position. The method therefore contains a procedure for calculating the

acoustic centre of a site, where it is practicable to do so.


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9.2.3 Noise Mapping and Propagation Model

European Directive 2002/49/EC specifies that the ISO 9613 propagation model should be used for

noise mapping purposes. This report does not therefore specify the fundamental propagation

algorithms that should be used. However, it is worthy to comment on one aspect of the standard with

respect to the mapping of industrial noise.

It should be recognised that currently, and in certain software packages, the simplified propagation

model using a single frequency, is implemented for propagation over soft (or mostly soft) ground. In

some cases, where propagation calculations are undertaken for hard ground using a single frequency,

then it may be necessary to map industrial noise using a modified version of this, as provided for in

Section 1, Note 1, of the standard. This could entail, for example, using full octave band calculations

but only populating the 500 Hz octave band with data. Thus when a noise modelling software

package is being used it is important to fully understand how the package interprets the detailed

algorithms in the standard.

10. RECOMMENDED MEASUREMENT METHOD

10.1 Scope

The determination of the sound power level of an industrial source by the proposed method is

intended solely for the purposes of industrial noise mapping for strategic purposes. Whilst the results

may have some use for planning and permitting requirements, it will invariably almost always be the

case that a much greater detailed level of modelling will be required for these applications.

10.2 Plant Operating Conditions

As the noise contours to be generated need to reflect the Lden,and Lnight parameters (which are annual

average values), both seasonal and day to day operating condition variations may need to be taken

into account. There will be some industries where operations can vary considerably depending on the

time of year. In this case, both or all scenarios should ideally be measured and an average sound

power value level determined. (In addition varying meteorological conditions will also need to be

taken into account to determine the resultant Lden and Lnight although consideration of this aspect does

not form part of this report). The duration of the relative operating conditions will play a part in the

decision as to whether or not to consider alternative operating scenarios. For example if a particular

operating condition takes place for only one week per year, then it can probably be ignored.


71

Decisions regarding the appropriate time to determine noise levels under typical operating conditions

will rely on either a good level of local knowledge and/or contact with the individual sites concerned.

Operating conditions of a plant may vary according to the following cycles:

Daily changes – i.e. higher output at certain times of the day;

Day / night changes – i.e. may output more / less during night;

Seasonal changes – i.e. may operate differently in summer / winter etc;

“Random” changes – on demand etc;

Upset conditions.

The resultant error in not determining sound power levels under all possible operating conditions for

the purposes of generating annual average levels may not be that great, as long as measurements

have been obtained for the typically highest noise output condition (for normal operations at the

industrial site) and an estimate made for the period of time when noise levels could be significantly

less than this. Occasional plant upset conditions, resulting in temporary higher noise levels, may not

necessarily affect yearly average values, although if local knowledge suggests that there is a

frequently occurring upset condition, then noise levels from this may need to be included in the long

term average values.

It should normally be possible, with some background knowledge of the particular industry involved, to

plan surveys around typical operating cycles. For example, liquefied natural gas facilities operate in

three distinct seasonal modes: gas liquefaction (during summer and off-peak gas demand periods),

gas export (during winter and high gas demand periods) and minimum operations. Likewise, certain

food processing plants etc may operate seasonally depending upon seasonal food supplies etc.

10.3 Meteorological Conditions

It will be necessary to conduct measurements under suitable weather conditions. Measurements

should normally be conducted under light wind speeds (average of 3 ms-1 or less) to minimise wind-

induced noise in the microphone and vegetation, as well as errors due to refraction of sound in one

particular direction. Where there is restricted access to one side of the site and there is a light wind

blowing during the survey then, ideally, there should be a downwind (or a crosswind) component of

the wind in the direction that measurements can be taken (i.e. the wind blowing from a northerly

direction). For example, if there is no access to the north side of a site for measurement, then a light

northerly wind would be appropriate for purpose. However the significance of the wind direction on

the measured noise levels will depend on the size of the site and the distance of the measurement

point from the noise sources. As a general rule, measurements of industrial noise will start to be


72

affected upwind of a noise source at a distance of 50 m or more under light wind. However,

temperature gradients also affect sound propagation and, for industrial noise spectra, useful

measurements at distances further upwind of the source may be viable if temperature inversion

conditions prevail (these occur typically under a clear sky at night). There should be no precipitation

during the measurement period, although a light passing shower may be acceptable.

10.4 Background Noise

Measurements should be conducted, where possible, at a time when the contribution from other noise

sources (e.g. road traffic, railways, aircraft etc) is at a minimum. This would normally be late at night

or early morning (but avoiding the effects of dawn chorus, for example). However, where a site either

does not operate during these times, or operates at a significantly reduced capacity, then

measurements would need to be taken at another time. Where the residual noise due to other

sources is thought to be affecting the measurement of noise from the industrial site, then correction

factors will need to be applied as described in Section 10.6.

10.5 Equipment

The following equipment specification is recommended as a minimum for measuring sound pressure

levels to calculate the sound power level of industrial premises:

An integrating-averaging sound level meter complying with the requirements of IEC 804 for a type 1

instrument should be used. As a minimum the meter should be capable of measuring overall (A-

weighted) Leq and L90 sound pressure levels although noise levels for other statistical indices

(particularly Lmax) will often be found useful when analysing the data.

The measurement microphone should be fitted with a windshield to minimise the effects of wind-

induced noise.

It has been assumed for the recommended measurement method that an omni-directional

microphone will normally be used.

During each series of measurements, an acoustic calibrator in accordance with IEC 942 class 1

should be applied to the microphone to verify the entire measuring system. Furthermore, the entire

measurement system should be electrically and acoustically calibrated over the entire measurement

frequency range at least within the previous 2 years.


73

10.6 Measurement Procedure

10.6.1 Close-Proximity (Site Boundary) Method

a) General

The close-proximity measurement method is preferred for measuring industrial noise sources in

residential areas, or where there are other potential noise sources nearby (e.g. roads and other

industry etc.).

It is particularly suitable where it is not possible to measure noise levels at distances further away

from the site of interest. Reasons for this may be:

Lack of publicly accessible measurement positions with direct line of sight to the site of

interest (e.g. obstructed by houses / barriers / bunds etc)

High background noise levels or other major noise sources prevent the source of interest

being audible from further away.

The measurement technique is based on the Stüber method, as implemented by ISO 8297, but

has been simplified in order to be more practicable to conduct.

b) Measurement Locations and Definition of Source

Measurements of sound pressure level should be conducted at various points on as much of a

closed contour around the plant as possible. Where measurements cannot be measured around

the complete boundary of the site, there is the potential for errors. Measurements should be

conducted at a height of at least 4 m above grade. Where practicable, and particularly where

local screening etc prevents a direct line of sight from the microphone to the site, such as next to

high walls / buildings etc. this height should be increased. In practice, and for a portable

measurement system, it is unlikely that measurements could easily be made with the microphone

at a height of more than 5 m above the ground.

Figure 27 shows the preferred measurement positions on a measurement contour around a plant,

where full access is available.


74

Measurement distance, d Measurement distance, d

Plant Area, Sp

Measurement Area, Sm

Largest dimension of plant area

Measurement distance, d

Measurement position, m

FIGURE 27: Measurement Positions For Close Proximity Method

The plant area, Sp, is defined as the smallest possible area containing the noise generating plant

or factory building. This will usually be less than the overall site area.

Where full access is available, measurements should be made at a minimum of 8 positions

around the plant and, where possible, evenly spaced. Where the difference in sound pressure

level between neighbouring measurement positions exceeds 6 dB(A)7, the number of positions

should be increased, if this is practicable.

The contour may be based on an elliptical, circular or a rectangular shape depending on access.

Reversals of curvature on the contour should be avoided, where possible. Where this is not

practicable, due to access restrictions etc, the number of measuring positions should be

increased. The mean radius of the contour (i.e. the average distance from the centre of the site to


75

7 Guidance from Reference 5

the measurement locations) should be less than 1 times the largest source dimension of the plant.

Otherwise, the distant measurement method should be used for the calculations (see below).

Measuring positions should only be used when noise from the industrial site is audibly dominant.

In some instances significant lengths of the contour may have to be eliminated and this will affect

the reliability of the determination. Care must be taken if there are nearby reflecting surfaces

(outside of the measurement contour) as these could distort the results.

In addition, a further measurement position(s) may be defined in order to measure, or allow an

estimate of, the residual noise. For this, it will be necessary to define a measurement position

where the ambient noise environment is presumed to be equivalent to the area around the site in

the absence of the site operating. This is similar to the approach taken in BS 4142 (Reference

15), where it is not possible to measure background noise at the assessment location.

Alternatively, it may be possible to measure residual noise levels directly, for instance if the

source operates intermittently etc.

c) Measurement of Sound Pressure Levels

Sound pressure levels should be measured in terms of LAeq. However, there may be some

occasions where there is a benefit to measuring noise from a site in terms of LA90, rather than

LAeq. Such a situation may be encountered, for example, where noise from the site is very steady

in nature, and where there is some time varying or intermittent residual noise.

Where use is made of the LA90 parameter for the approximation of the LAeq value of the steady

industrial sound in the presence of other time varying non-industrial noise sources, then a small

correction factor may be necessary to the measured LA90 value to represent the LAeq value of the

industrial source. In most cases this correction will be 1 – 2 dBA, and can be best determined

from short-term measurements when other noise sources can be ignored.

Where LA90 measurements are made in lieu of LAeq measurements, then corrections for residual

noise should still be made as, in this case, the LA90 parameter is an approximation of the specific8

or residual noise level.

The measurement time chosen will depend on local conditions and the noise source(s) of interest.

Where the noise is steady, it will be possible to take very short measurements (say around 1 - 2

minutes, using the pause facility on the sound level meter, if it contains this feature). This can

8 As defined in Reference 15


76

help reduce interference from other noise sources such as intermittent traffic noise, aircraft and

local activity as measurements can easily be fitted in between events. For time varying, cyclic or

intermittent noise, however, it will be necessary to measure for longer time periods. Where

possible, noise measurements should be made over at least two cycles of operation.

Where mobile noise sources (e.g. moving vehicles, excavators, etc) are present on site, the

measurement period should be extended to allow an averaging out of noise from the source. In

some cases, this will be similar to the treatment of cyclic sources and simply require a

measurement over one or two ‘journeys’. However, where the moving source travels ‘randomly’

around the site, judgement should be made, based on local conditions, as to the required

measurement length. For example, it may be that the effects due to mobile sources are cancelled

out due by increasing the number of measurement positions around the site. Alternatively,

utilising the far-field measurement technique below can reduce the effect of a mobile source.

d) Calculation of Sound Power Level

Where an assessment has been made of residual noise, each sound pressure measurement

should first be corrected for this, using the formula:

[ ]21 1.01.0* 1010log10 pppL −=

where is the corrected sound pressure level, p*pL 1 is the sound pressure of the industrial noise

plus residual noise, and p2 is the residual sound pressure (in the absence of the industrial noise).

Calculate the average boundary sound pressure level, pL , using the following formula, where L*p,i

is the sound pressure level at the ith measurement position, corrected for residual noise:

( )

= ∑

=

n

i

Lp

ip

nL

1

1.0 *,101log10

Next, calculate an area term, SL∆ , using the following formula:

+=∆

0

2log10S

hlSL mS

Sm = measurement area, m2

h = characteristic height of plant, m


77

l = measurement contour length, m

S0 = reference area equal to 1 m2

The next step is to calculated a correction term for atmospheric absorption, , using the

following formula:

αL∆

10005.0 mS

Lα

α =∆

where α = atmospheric absorption coefficient at 500 Hz, as defined in ISO 9613-2, to be taken as

~2 dBkm-1 for normal conditions.

The proximity correction term, FL∆ , can be calculated using the formula:

=∆

pF S

dL4

log

where Sp = the plant area in m2 and d = the average measurement distance in m (see Figure 27).

Finally, the sound power level, Lw, is calculated from the following equation:

αLLLLL FSpw ∆+∆+∆+=

In many cases, the term hl in the equation for sL∆ can be ignored. For example, for an

industrial plant with typical measurement dimensions of 200 m by 100 m and a mean noise

source height of 5 m, the error in omitting the term hl is less than 1 dB. As the plant size

becomes smaller and the source height increases, then the error becomes greater if this term is

deleted. For a plant with dimensions 40 m by 40 m and a mean source height of 10 m, the

potential error is 3 dB if this term is omitted.

Worked Example:

Figure 28, below, shows a simple site layout, with 10 measurement points on a contour. In this

case, the plant area dimensions are 100 x 60 m, and the measurements were taken at a distance

of 5 m from the boundary of the plant area. The measurements were approximately 30 m apart

and the average sound pressure level ( pL ) was 50 dB(A).


78

Plant

7 6

5

4

8

9

10

1 32

Plant

7 6

5

4

8

9

10

1 32

FIGURE 28: Worked Example – Close Proximity Method

Based on the above scenario, Sm = 7,700 m2 and Sp = 6,000 m2, and for h = 4m:

SL∆ = 42.3, = 0.1, = -1.0 αL∆ FL∆

Hence, Lw = 50.0 + 42.3 + 0.1 - 1.0 = 91.3 dB(A)

If the height term, hl, is ignored in the above calculation, then SL∆ = 41.9

Hence, Lw = 50.0 + 41.9 + 0.10 - 1.0 = 91.0 dB(A)

The error in this case is 0.4 dB(A) (rounded from 2 decimal places). If the average source height

is 10 m then the error becomes 1 dB(A).

10.6.2 Distant Measurement Method

a) General

The distant measurement method is suitable for measuring industrial noise sources in open areas

where there is direct line of sight to the site in several directions for distances greater than one

times the largest source dimension from the geometric centre of the site. However, noise from

other sources should be insignificant compared with noise from the site for this method to be valid

(typically 10 dB less), or be corrected for, if an estimate of residual noise can be made.

The measurement technique is based on hemispherical sound propagation and can be modified

for soft ground etc if required.


79

b) Measurement Location

Measurements of sound pressure level should be conducted at a distance of at least one times

the largest source dimension from the geometrical centre of the site. Normally, four directions will

suffice, although this may be increased if the source is thought to be highly directional in one

particular direction. Measurements should be conducted at a height of at least 4 m above grade.

Measurement locations should be chosen such that there is a direct line of sight to the site.

Figure 29, below, shows the measurement positions on a measurement contour around a plant.

Measuring positions should be eliminated where there is interference from other noise sources,

such as other industrial premises or roads etc.

Where possible, an additional set of measurements should be taken at an even further distance,

m, back from the plant, in each general direction. Typically, four measurements (north, south,

east and west) should be conducted, although this may depend on access. These measurements

should preferably be taken at a distance of more than 1.5 times the largest source dimension from

the centre of the plant. The purpose of these measurements is to identify the acoustic centre of

the site and to help define true directivity (see 10.6.3).

Plant Area

Geometric centre of plant

Largest source dimension Measurement position, m

Measurement distance, d

FIGURE 29: Measurement Positions For Distant Measurement Method


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In addition, further measurement positions may be defined in order to measure residual noise.

For this, it will be necessary to define measurement positions where residual noise is presumed to

be equivalent to that in the vicinity of the site. This is similar to the approach taken in BS 4142,

where it is not possible to measure background noise at the assessment location. Alternatively, it

may be possible to measure residual noise levels directly, for instance if the source operates

intermittently etc.

c) Measurement of Sound Pressure Levels

Sound pressure levels should be measured in terms of LAeq. However, there may be some

occasions where there is a benefit to measuring noise from a site in terms of LA90, rather than

LAeq. Such a situation may be encountered, for example, where noise from the site is very steady

in nature, and where there is some time varying or intermittent ambient noise. As for the close

proximity measurements, a simple correction to the measured LA90 level may be applied to

represent the LAeq value due to the industrial source. This will usually be an increase of 1 - 2 dB.

The measurement time chosen will depend on local conditions and the noise source(s) of interest,

as defined for the close proximity measurements, above. However, it is likely that a longer

measurement time will be more appropriate for far-field measurements in order to account for any

variations due to meteorological conditions etc.

d) Calculation of Sound Power Level

Where an assessment has been made of residual noise, each sound pressure measurement

should first be corrected for this, using the formula:

[ ]21 1.01.0* 1010log10 pppL −=

where is the corrected sound pressure level, p*pL 1 is the sound pressure of the industrial noise

plus residual noise, and p2 is the residual sound pressure (in the absence of the industrial noise)

If it was only possible to measure at one distance from the source in each direction, then the

following procedure should be applied. Otherwise, the procedure defined in Section 10.6.3,

below, should be followed.

The apparent sound power level in the ith direction can be calculated using the formula:


81

[ ] gri

iipiW AddLL +++=1000

2log10 2*,

',

απ

where di = source to measurement distance and α = atmospheric absorption coefficient at 500

Hz, as defined in ISO 9613-2, to be taken as ~2 dBkm-1 for normal conditions. Where the ground

cover between the source and measurement position is mostly soft ground, an appropriate

correction (Agr) should be made for this using the formula:

03001728.7 ≥

+⋅

−=

ddhA m

gr

where hm is the mean height of the propagation path above ground, in meters. Where the

formula for Agr gives a negative value, this should be normalised to 0.

The average apparent sound power level WL can be worked out using the following equation:

( )

= ∑

=

n

i

Lw

iw

nL

1

1.0 ',101log10

From this, it is possible to work out the apparent directivity of the source in a particular direction

(DIi) by using:

WiWi LLDI −= ,

10.6.3 Refined Distant Measurement Method

In order to calculate the true directivity of the source, it is first of all important to differentiate between

true directivity and errors due to source proximity effects (i.e. being closer to a major source at one

measurement point than at another). The reason for this is because directivity effects may well affect

distant receiver points, although source proximity effects reduce with distance from the source.

The first step is therefore to define the acoustic centre of the source in each direction. Normally, four

directions will suffice (although this may be increased if the source is thought to be highly directional

in one particular direction). To do this, four additional measurements will need to be carried out, one

each in the north, south, east and west axes. These second set of measurements should be

conducted at a distance of at least one and a half times the typical source dimension from the


82

geometrical centre of the site. The distance to the acoustic centre of the site, Dcentre can then be

worked out according to the following equation:

110

10

20

20

−

×∆= ∆

∆

pL

pL

centredD

where = distance between measurement points and d∆ pL∆ = difference between sound pressure

levels. No correction has been made for atmospheric absorption or ground effects in this equation.

Atmospheric absorption effects are not likely to be significant, and over hard ground, no correction is

required for ground effects. However, over soft ground a correction factor is required to pL∆ ,

although the magnitude of this depends on the mean propagation path and the absolute distance of

the measurement point from the noise source. For typical industrial noise spectra, and for a mean

propagation height of 2m, no correction factor is necessary if both measurement distances are 500m

or more from the assumed location of the noise source. For measurements closer to the noise source

then a correction factor for ground effects needs to be applied to the parameter, based on the

difference in ground effect values according to ISO 9313-2.

pL∆

Worked Example:

Figure 30 shows two measurements to the east of a site, along with distances to the centre of site and

the measured sound pressure level at each location.

ACOUSTICCENTRE d1 = 50 m

50 dB(A)

d2 = 100 m45 dB(A)

Dcentre

ACOUSTICCENTRE d1 = 50 m

50 dB(A)

d2 = 100 m45 dB(A)

Dcentre

GEOMETRIC

CENTREGEOMETRIC

CENTRE

FIGURE 30: Worked Example – Refined Distant Method

From the figure, d∆ = 50 m and pL∆ = 5 dB(A).

Therefore,

110

1050

205

205

−

×=centreD = 114 m


83

Once the distance to the acoustic centre has been calculated, it is possible to calculate the “apparent

sound power level” in each direction by using hemispherical propagation plus atmospheric absorption

using the following equation (where L’W,i is the apparent sound power level in the ith direction):

[ ]1000

2log10 2',

centrecentrepiW

DDLL απ ++=

where α = atmospheric absorption coefficient at 500 Hz, as defined in ISO 9613-2, to be taken as ~2

dBkm-1 for normal conditions. Where the ground cover between the source and measurement

position is mostly soft ground, an appropriate correction (Agr) should be made for this using the

formula:

03001728.7 ≥

+⋅

−=dd

hA mgr

where hm is the mean height of the propagation path above ground, in meters, and d is the source to

receiver distance, in meters. Where the formula for Agr gives a negative value, this should be

normalised to 0.

The average apparent sound power level WL can be worked out using the following equation:

( )

= ∑

=

n

i

iwLw n

L1

,1.0101log10

From this, it is possible to work out the true directivity of the source in a particular direction (DIi) by

using:

iWWi LLDI ,−=

It should be noted that in an upwind direction from the noise source, and even in very light winds, the

sound pressure level close to the ground can decrease rapidly due to upwards sound diffraction

effects. This may skew the results obtained and lead to errors. If there is any doubt, more reliance on

determining the acoustic centre of the industrial plant should be placed on the downwind noise

measurements.


84

11. APPLICATION OF DATA

11.1 General

Industrial noise mapping will be carried out using the ISO 9613 propagation model. It is not in the

scope of this project to investigate this method or to comment on its suitability. Therefore, the only

aspects of mapping to be considered are restricted to the distribution of the sound power data, since

the propagation thereafter is “in the hands of” ISO 9613.

When modelling, it is recommended that the industrial noise source of concern be represented by

distributing the measured sound power in a manner as similar as possible to the real situation.

Therefore, if the original source is known to be an elevated point source (e.g. a stack) then the sound

power should be distributed in the computer model as such. Likewise, for large factory buildings etc.

the sound power should be distributed over the façades, with a correction for directivity. A more

comprehensive list is given in Table 14:

Type of Industry Site Probable Method of Representing Source Large Factory Smeared over façades and roof of building Open Site 2D Area Source Stacks Elevated Point Source (Or elevated area source

for multiple stacks) Mobile Source (Site traffic or moving excavator) Line or Area Source

TABLE 14: Suggested Methods of Representing Different Types of Industrial Source for Noise Mapping

Where it is not possible to determine the distribution of the noise source, the sound power should be

distributed as a 2D area source. The height of the source will need to be judged by the surveyor.

When representing the source as a point source, the preferred location of the source is the acoustic

centre, rather than the geometric centre of the source. However, the geometric centre may be used if

the distant measurement method was used to determine the sound power level of the source. Where

the close-proximity method was used to determine the source strength, then the source should be

represented by a 2D area source. Alternatively if it were represented as a point source, than an

estimate needs to be made of the location of the acoustic centre.

Directivity should also be assigned to the source wherever practicable. Typically, the average

apparent sound power level would be assigned to either the point or area source(s). The directivity

index, DIi should then be applied to each direction (i).


85

11.2 Intermittent operation of industrial noise sources

Consideration has been given as to how to account for industrial noise sources which do not operate

continuously during each time period i.e. day, evening and night. In terms of how this needs to be

accounted for mathematically, it is considered that a BS 5228 (Reference 16) percentage on-time type

correction would be appropriate. This is a simple time factor correction. For example, if a source

were to operate for half of the relevant time period, then a –3dB correction would be applied.

Some thought has been given to how appropriate measurements can be conducted to account for

sources that do not operate continuously. It is anticipated that this may pose a difficulty as it relies

either on a reasonable level of local knowledge as to when sources are operational (for example an

Environmental Health Officer may be able to provide this information). Alternatively it may be

necessary to contact the site to discuss operating conditions, which relies on the co-operation of the

industry. It may be necessary to conduct measurements for a number of operating conditions,

although this would be minimised by good local knowledge.

12. CONCLUSIONS

A method has been developed to allow modelling of noise from industrial sources for the purposes of

strategic noise mapping. The method was developed based on the results of extensive noise

modelling carried out to investigate the errors inherent in determining and distributing source

strengths and the subsequent modelling of the propagation of sound. The modelling investigated the

influence of:

Measurement location relative to plant (distance and height);

Number of measurement locations;

Spatial distribution of plant noise sources;

Spectral content of plant noise;

Topography and ground cover;

The effects of relative humidity and temperature.

The views of Local Authorities in England have also been canvassed for their subjective impressions

about industrial noise sources in their area. The local authority responses identified some 300

industrial sites across England that the Local Authorities considered to be affecting their areas. Of

those 300 sites, approximately half were considered to be significant sources of noise in that area.

The research showed that 78% of these sites were associated with tonal, impulsive or low frequency


86

characteristics. It has therefore been concluded that it is important to take account of these

characteristics for industrial noise to be assessed fully.

Research has also been conducted to investigate non-acoustic means of source strength

determination, including a review of European work on this subject. At present, it is not considered a

viable proposition in England to use non-acoustic means to determine noise source strengths. It is,

however, possible that such a method might be developed in due time in the light of more extensive

experience of determining and averaging site source strengths.

The results of the modelling show that, in general, a single band approximation of the propagation of

sound offers a relatively accurate approximation for industrial noise. It is therefore recommended that

the mapping of industrial noise for strategic purposes be conducted using overall dB(A) values with

attenuation terms for the 500 Hz octave band used to estimate the resulting attenuation. It must be

stressed that this relatively simplistic approach should only be used for this application. More detailed

measurements will almost always be necessary to investigate a particular noise issue.

As part of the project, different methods of source strength determination were researched.

Investigations consisted of computer based modelling as well as measurement exercises. The results

of the modelling and site exercises illustrate that source determination can be carried out utilising both

close-proximity (i.e. site boundary) and distant measurements. However, a correction for ground

effects is necessary when using distant measurements over soft ground.

In terms of the subsequent distribution of the source sound power for the purposes of noise mapping,

the research established that the most accurate way of modelling a noise source is by distributing the

sound energy in a manner as similar as possible to the real situation. However, where this is either

not practicable, or the true sound power distribution is not known, a reasonable degree of accuracy

can be obtained by modelling the sound power as either a 2 dimensional area source or a point

source.

The results of the modelling indicated that the directivity of the source can significantly influence the

accuracy of the calculated values of the noise contours. For this reason, the proposed method

includes provision for determining the acoustic centre and directivity of the source.

It is concluded that the proposed methodology allows consistent and reasonably accurate

representation of industrial noise sources for noise mapping. This will provide the necessary firm

basis for assessing the effects of industrial noise and mitigation where this is considered necessary.


87


GLOSSARY

Abreviation Definition Unit

Aatm Atmospheric attenuation dB Adiv Attenuation due to geometric divergence dB d Measurement distance m

Dcentre Distance to acoustic centre of site m DIi Directivity index in ith direction dB G Ground factor - h Measurement height m H Average height of plant’s noise emitting equipment m hm Mean height of sound propagation m l Measurement contour length m

L90 Sound pressure level exceeded for 90% of the time (i.e. background level)

dB

LAeq Equivalent sound pressure level dB Lp Sound pressure level dB Lw Sound power level dB Lw’’ Sound power level per unit area dBm-2 Sm Measurement area m2 Sp Plant area m2

SPM Sound power per square meter dBm-2 ∆LF Proximity correction term dB ∆Ls Area correction term dB ∆Lα Atmospheric absorption term dB α Atmospheric absorption coefficient dBkm-1

REFERENCES

Reference

No. Author / Standard No. Title Date

1 END European Noise Directive 2002/49/EC 2002 2 Defra Towards a National Ambient Noise Strategy 2001 3 ISO 9613-2 Acoustics -- Attenuation of sound during propagation

outdoors -- Part 2: General method of calculation 1996

4 ISO 8297 Acoustics -- Determination of sound power levels of multisource industrial plants for evaluation of sound pressure levels in the environment -- Engineering method

1994

5 EEMUA Noise Procedure Specification Publication No. 140 1985 6 CONCAWE Report No. 2/76 - Determination of Sound Power Levels

of Industrial Equipment, Particularly Oil Industry Plant 1976

7 ISO 3744 Acoustics -- Determination of sound power levels of noise sources using sound pressure -- Engineering method in an essentially free field over a reflecting plane

1994

8 ISO 3746 Acoustics -- Determination of sound power levels of noise sources using sound pressure -- Survey method using an enveloping measurement surface over a reflecting plane

1995

9 Salford Sources of Magnitude of Uncertainty Arising in thePractical Measurement of Environmental Noise

2001

10 Defra Noise Climate Assessment: A review of National and European Practices

1999

11 Danish Acoustical Institute Report No. 105 - Noise Immision from Industry –Measurement and Prediction of Environmental Noise from Industrial Plants.”

1982

12 DTI Energy – its impact on the environment and society 2003 13 DTI UK Energy Sector Indicators 2003 – A supplement to

the Energy White Paper, Our energy future. Creating a low carbon economy

2003

14 VDI 3733 Geräusche bei Rohrleitungen 1996 15 BS 4142 Method for rating industrial noise affecting mixed

residential and industrial areas 1997

16 BS 5228 Noise and vibration control on construction and open sites.

1997

17 BS 7445-1 Description and measurement of environmental noise. Guide to quantities and procedures

1991

18 IPPC Concerning integrated pollution prevention and control 96/61/EC

1996

19 de Bakom A report on the production of noise maps of the City of Birmingham.

2000


Reference No.

Author / Standard No. Title Date

20 Environment Agency Horizontal Guidance for Noise (IPPC H3) 2002 21 ISO 9613-1 Acoustics -- Attenuation of sound during propagation

outdoors -- Part 1: Calculation of the absorption of sound by the atmosphere

1993

22 Technical Research Centre of Finland

A Measurement Procedure Proposal For Emission of External Noise From Large Industrial Sources

1981

23 Stüber Measurement Methods for Determining the Acoustic Capacity of Extensive Sound Sources

1972

24 Crocker, Malcom J. Identification of Noise From Machinery, Review of Novel Methods - Internoise 77

1977

25 Witte, R and Ouwerkerk, M Comments on ISO 9613-2 - Internoise 96 1996 26 Defra Noise Mapping: Experience in Germany and its

Relevance to the UK 1999

27 Richards, J. Measurement of Sound Power of Large Industrial Noise Sources

28 Wolde, T. On the Measurement od Source Strength of LargeIndustrial Sources, Internoise 78

1978

29 Nordforsk Noise From Industrial Plants 1984 30 Danish Acoustical Institute Report No. 32 - Environmental Noise from Industrial

Plants General Prediction Method 1982

31 Witte, R Controlling Noise Immission for Large Industrial Areas, Internoise 97

1997

32 DELTA Nordic Environmental Noise Prediction Methods, Nord200 Summary Report

2001


APPENDIX 1

Local Authority Questionnaire


Acoustic Technology Our ref: AT5414/BCP/23652 24th March 2003 «Authority» «Address» For the attention of the Principal Environmental Health Officer Re: DEFRA Research Contract on Industrial Noise Mapping Techniques You may be aware that, following the Defra Consultation Paper “Towards a National Ambient Noise Strategy” published in November 2001, the Government has announced its intention to move forward in developing a national ambient noise strategy in England. Phase 1 of the strategy includes the mapping of the main sources and areas of noise in order to establish the ambient noise climate in this country, and determine the number of people affected by different levels of noise, the source of that noise (road, rail, airports and industry) and the location of the people affected. Whilst established methods exist in this country with regard to noise from roads, railways and aircraft, there is no similar standardised method to determine noise of an industrial origin. Defra has therefore awarded a research contract to Bureau Veritas to investigate the feasibility of representing industrial noise sources in a strategic noise map that is simple, reproducible and robust. Our contacts at Defra are John Stealey (tel 020 7944 6307) and Stephen Turner (tel 020 7902 6176). We are seeking help from Local Authorities, industry and other stakeholders, to define what are perceived to be the major sources of industrial noise in this country, and to identify any relevant noise data that are already available, and the methods by which the data were obtained. We would be grateful, therefore, if you could spend a few minutes completing the attached questionnaire, indicating what you consider to be the major industrial noise sources affecting your authority’s area, and return it to us in the supplied envelope. Where you have any noise data readily available relating to the sound power levels of the major industrial plant affecting your area, then we would be pleased if you could attach a copy of it (maintaining confidentiality as appropriate). We are interested, in particular, in octave band spectra for the noise radiation characteristics of different types of industrial plant and the spatial distribution of the noise sources on the site. If you do not hold any such noise data yourself, but you are aware that other (third parties) may do so (e.g. technical consultants or the industry itself) perhaps you could indicate this so we could make contact directly with the relevant party. Thank you for any assistance you can give us. Yours sincerely BV ACOUSTIC TECHNOLOGY

Bernard Postlethwaite Principal Consultant

DEFRA Research Contract on Industrial Noise Mapping Techniques, Questionnaire, Page 1 of 2

Local Authority: Contact Name: Telephone No:

Date of Completion: E-mail Address: Fax No:

What do you consider to be the top three major noise emitting industrial sites affecting your authority’s area? In completing this questionnaire, please place the emphasis on the larger industrial sources e.g. power stations, manufacturing plant (which are potentially audible over a wider area and may possibly affect a large number of people, although may not necessarily be a source of frequent complaint) as compared to industrial noise sources that may give rise to frequent complaints from one or two individuals e.g. a small scrap metal yard. In completing the questionnaire, please include all types of industrial sources including ports, manufacturing plant, process plant, mineral extraction and waste disposal sites etc. Where the site includes more than one operator, please indicate this, giving the prime operator, if possible. If your area is not affected by any major industrial noise sources, we would still like to hear from you, with what you consider to be the most significant industrial noise in your area. Where appropriate, please circle or tick the relevant response. Thanks for your help. Industrial Site 1 Industrial Site 2 Industrial Site 3

1. Name of site or plant: 2. Type of industry: 3. Is there more than one operator involved? If so please specify prime operator, if known:

YES NO Major Operator:

YES NO

Major Operator:

YES NO

Major Operator:

4. Operating periods: Day Evening Night Day Evening Night Day Evening Night

5. Does this industrial site have any distinguishing acoustical features?

Tonal / Impulsive / Low Frequency Other (please specify):



6. Do you have any noise data relating to this site?

YES NO If NO, skip to Question 12.



7. What form does this data take?

dBA levels at community point; octave band levels at community point; dBA sound power levels of plant; octave band sound power levels of plant; not sure at present; other (please specify):



AT5414/BCP//Questionnaire/Rev1

AT5414/BCP//Questionnaire/Rev1

DEFRA Research Contract on Industrial Noise Mapping Techniques, Questionnaire, Page 2 of 2

8. If sound power level data is available, do you know how this was obtained?

YES NO YES NO YES NO

9. Are you prepared to make this data available as part of the Defra research contract?


10. Do you think it would be necessary to keep the identity of the plant anonymous?


11. Have you attached any data with this response?


12. Are you aware of other available noise data for this site? If YES, please specify the sources with contact names and tel. nos.

YES NO Other Contact: Tel No:



13. Do you consider the chosen industrial site to be a significant source of environmental noise concern?


14. How frequently do you receive complaints about noise from this site?

Frequently / Sometimes / Rarely / Never Frequently / Sometimes / Rarely / Never Frequently / Sometimes / Rarely / Never

15. Is this plant, or site, in your authority’s area?


16. Would you be willing for us to telephone or E-mail you to discuss these issues further?


APPENDIX 2

Stakeholder Contact Letters


Acoustic Technology Our ref: AT5414/AMR/23651 21st March 2003 «Title» «FirstName» «LastName» «Company» «Address1» «Address2» «City» «PostalCode» Dear «Title» «LastName» Re: DEFRA Research Project on Industrial Noise Mapping Techniques You may be aware that, following the Defra Consultation Paper “Towards a National Ambient Noise Strategy” published in November 2001, the Government has announced its intention to move forward in developing a national ambient noise strategy in England. Phase 1 of the strategy includes the mapping of the main sources and areas of noise in order to establish the ambient noise climate in this country, and determine the number of people affected by different levels of noise, the source of that noise (road, rail, airports and industry) and the location of the people affected. Whilst established methods exist in this country with regard to noise from roads, railways and aircraft, there is no similar standardised method to determine noise of an industrial origin. Defra has therefore requested Bureau Veritas to investigate the feasibility of representing industrial noise sources in a strategic noise map that is simple, reproducible and robust. Our contacts at Defra are John Stealey (tel 020 7944 6307) and Stephen Turner (tel 020 7902 6176). During the course of the research project we will be keeping relevant stakeholders, including your organisation informed, of our progress and will welcome comments regarding our proposed approach to industrial noise mapping. If you consider there is another individual in your organisation who should be contacted as well as or instead of yourself, then please pass on this letter or send their contact details to one of the following email addresses: [email protected] or [email protected]. Thank you for your interest. Yours sincerely BV ACOUSTIC TECHNOLOGY Bernard Postlethwaite Principal Consultant

APPENDIX 3

European Government Departments Contact Letters


Acoustic Technology Vor ref: AT5414/AMR/23664 1st April 2003 Danish Environmental Protection Agency Transport & Air Quality Division 29 Strandgade DK-1401 Copenhagen K Denmark Att.: Hugo Lyse Nielsen Kære Hugo Lyse Nielsen Vedr.: DEFRA forskningsprojekt vedrørende kortlægningsteknikker for virksomhedsstøj I England har Defra, (Department for the Environment, Food and Rural Affairs), ministeriet for miljø, fødevarer og landbrug, ansvaret for at beskytte og forbedre miljøet og integrere politik vedrørende disse problemer med andre på tværs i regeringen og internationalt. Efter Defras høringsoplæg "På vej mod en national strategi for baggrundsstøj", som blev publiceret i november 2001, har regeringen offentliggjort sin hensigt om at gå videre med udviklingen af en national strategi for baggrundsstøj i England. Strategiens fase 1 omfatter kortlægning af de vigtigste kilder til og områder for støj for at etablere et klima for baggrundsstøj i England. Den vil fastslå antallet af mennesker, som berøres af forskellige støjniveauer, støjens kilde (vej, jernbane, lufthavne og industri) og de berørte menneskers placering. Arbejdet skal også tjene det formål at opfylde de indledende krav i det europæiske støjdirektiv, 2002/49/EC. Selv om der findes etablerede metoder i England med hensyn til støj fra veje, jernbaner og fly, findes der ingen lignende standardiseret metode til at fastslå støj af industrimæssig oprindelse. Defra har derfor anmodet Bureau Veritas Acoustic Technology om at undersøge muligheden for at afbilde industrimæssige støjkilder i et strategisk støjkort med anvendelse af en metodik, som er enkel, reproducerbar og robust. Som en del af dette projekt kontakter vi de relevante ministerier i en række andre europæiske lande for at afgøre, hvilket lignende arbejde, der er udført eller i øjeblikket er undervejs. Vi vil derfor være taknemlige, hvis De kunne forsyne os med oplysninger om eventuelle metodikker, der anvendes i Deres land til at bestemme lydeffektniveuet for industrielle støjkilder i forbindelse med strategisk støjkortlægning. Vi er interesserede i teknikker, der er baseret på måling eller ikke-akustiske metoder (dvs. procesinformation, energiforbrug, osv.). Vi vil desuden være taknemlige for at få kendskab til eventuel strømforskning vedrørende lydeffektniveaumåling af industrielle støjkilder til kortlægning af støj. Projektteamet kan kontaktes pr. telefon, fax eller brev og på følgende e-mail-adresser: [email protected], [email protected], [email protected].

-2- Vor ref: AT5414/AMR/23664 1st April 2003 Hvis De mener, at der er en person i Deres organisation, som også skal kontaktes, eller som skal kontaktes i stedet for Dem selv, beder vi Dem videregive dette brev eller sende os kontaktoplysninger om vedkommende. Vi takker for Deres interesse og samarbejde. Venlig hilsen BV ACOUSTIC TECHNOLOGY Bernard Postlethwaite Ledende konsulent

Acoustic Technology Notre réf: AT5414/AMR/23662 31st March 2003 Ministry of County Planning and Environment Ministere de l'Ecologie et du Developpement Durable, 20 Avenue de Segur, 75302 Paris 07 SP, France À l'attention de David Delcampe Monsieur/Madame Réf : Projet de recherche DEFRA sur les techniques de cartographie du bruit industriel Defra, le ministère britannique de l'Environnement, de l'Alimentation et des Affaires rurales, est chargé en Angleterre d'assurer la protection et l'assainissement de l'environnement, ainsi que l'intégration des programmes relatifs à ces questions avec d'autres organismes à l'échelon gouvernemental et international. À la suite du document de consultation intitulé “Vers une stratégie nationale concernant le bruit ambiant” publié en novembre 2001, le gouvernement britannique a annoncé son intention de se mobiliser pour développer une stratégie nationale concernant le bruit ambiant en Angleterre. La première phase de cette stratégie porte sur la cartographie des principales sources de bruit et des zones de bruit afin d'établir le climat de bruit ambiant en Angleterre. Elle permettra de préciser le nombre d'habitants affectés par différents niveaux de bruit, les sources de ce bruit (infrastructures routières, ferroviaires, aéroports et industrie) et l'emplacement des personnes affectées. Ces travaux serviront également à satisfaire aux conditions initiales de la Directive européenne 2002/49/CE relative à la gestion du bruit. Bien qu'il existe en Angleterre des méthodes bien établies concernant la gestion du bruit provenant des infrastructures routières, ferroviaires et des aéronefs, il n'y a aucune méthode standardisée similaire permettant d'établir les niveaux de bruit d'origine industrielle. Defra a donc demandé à Bureau Veritas Acoustic Technology d'explorer la faisabilité de représenter les sources de bruit industriel sur une carte stratégique du bruit selon une méthodologie qui soit simple, répétable et robuste. Dans le cadre de ce projet, nous nous mettons en contact avec les ministères appropriés de divers autres pays européens afin d'établir quels travaux d'ordre similaire ont été entrepris ou sont en cours. Nous vous serions donc reconnaissants de bien vouloir nous fournir des renseignements détaillés sur toutes méthodologies utilisées dans votre pays permettant d'établir le niveau de puissance acoustique des sources de bruit industriel par rapport à une cartographie stratégique du bruit. Nous nous intéressons aux techniques basées sur des mesures ou des moyens non acoustiques (ex. informations sur les procédés, consommation électrique, etc.). Et de même, nous vous prions de bien vouloir nous indiquer toutes les recherches actuelles relatives à l'établissement des niveaux de puissance sonore des sources de bruit industriel en vue d'établir une cartographie du bruit. Vous pouvez contacter les membres de l'équipe de ce projet au téléphone, par fax ou par la poste, et aux adresses email suivantes : [email protected], [email protected], [email protected].

-2- AT5414/AMR/23662 31st March 2003 Si vous pensez qu'il nous serait utile de contacter par ailleurs une autre personne appartenant à votre organisme, veuillez lui transmettre cette lettre ou nous envoyer ses coordonnées. Nous vous remercions de votre attention et de votre coopération. Nous vous prions d'agréer, Monsieur/Madame, l'expression de nos sentiments distingués BV ACOUSTIC TECHNOLOGY

Bernard Postlethwaite Consultant Principal

Acoustic Technology Ons kenmerk: AT5414/AMR/23663 1st April 2003 Dutch Ministry of Housing Spatial Planning and the Environment PO Box 20951 2500 EZ Den Haag Netherlands Ter attentie van Martin Van den Berg Geachte Martin Van den Berg Betreft: DEFRA Researchproject naar technieken voor het opstellen van industriële geluisbelastingkaarten In Engeland is het Department for the Environment, Food and Rural Affairs, Defra, verantwoordelijk voor de bescherming en verbetering van het milieu en het integreren van het beleid ten aanzien van deze kwestie met andere beleidslijnen van de Britse regering en de regeringen van andere landen. Naar aanleiding van het document “Towards a National Ambient Noise Strategy” van Defra, dat in november 2001 gepubliceerd werd, heeft de regering bekendgemaakt dat zij van plan is een nationale omgevingslawaaistrategie in Engeland te ontwikkelen. Fase 1 van de strategie omvat onder meer het in kaart brengen van de belangrijkste lawaaibronnen en de regio’s waar het hoogste lawaainiveau gemeld is, om het omgevingslawaaiklimaat in Engeland te identificeren. Aan de hand van deze gegevens kan worden vastgesteld hoeveel mensen worden blootgesteld aan de verschillende lawaainiveaus, wat de bron van het lawaai is (wegen, spoorwegen, luchthavens en industrie) en waar deze mensen wonen. Het werk zal tevens helpen te voldoen aan de eerste bepalingen van de Europese richtlijn Omgevingslawaai: 2002/49/EG. Hoewel er in Engeland reeds gevestigde methoden bestaan met betrekking tot lawaai veroorzaakt door weg-, trein- en luchtvervoer, bestaat er geen equivalente, gestandaardiseerde methode voor het evalueren van het lawaainiveau uit industriële bronnen. Derhalve heeft Defra Bureau Veritas Acoustic Technology gevraagd de haalbaarheid te onderzoeken van een evaluatiemethode aan de hand waarvan industriële lawaaibronnen in een strategische geluidsbelastingkaart vastgelegd kunnen worden middels een methode die eenvoudig, herhaalbaar en robuust is. Als onderdeel van dit project nemen wij contact op met de relevante regeringsinstanties van een aantal andere Europese landen teneinde vast te stellen welke soortgelijke projecten zijn of worden uitgevoerd. Wij zouden het derhalve ten zeerste op prijs stellen indien u ons informatie wilt verstrekken over enige methoden die in uw land aangewend worden voor het evalueren van het geluidsbelastingniveau ten behoeve van het opstellen van strategische geluidsbelastingkaarten. We zijn geïnteresseerd in technieken op basis van metingen of niet-akoestische middelen (bijv. procesinformatie, energieverbruik, enz.). Verder zouden wij ook graag informatie ontvangen over enig onderzoek met betrekking tot de evaluatie van het geluidsbelastingniveau ten behoeve van strategische geluidsbelastingkaarten. Het projectteam is telefonisch, per fax, schriftelijk of op de volgende e-mailadressen te bereiken: [email protected], [email protected], [email protected].

Ons kenmerk: AT5414/AMR/23663 1st April 2003

2

Mochten er in uw organisatie nog andere personen zijn met wie wij, naast of in plaats van uzelf, ook contact zouden moeten opnemen, geeft u deze brief dan aan hen door of stuur ons hun contactgegevens. Vriendelijk dank voor uw interesse en medewerking. Hoogachtend BV ACOUSTIC TECHNOLOGY Bernard Postlethwaite Hoofdconsulent

Acoustic Technology Unsere Ref: AT5414/AMR/23665 1st April 2003 Federal Environment Agency Umweltbundesamt Postfach 33 00 22 14191 Berlin Germany Zu Händen von Volker Imer Sehr geehrte(r) Volker Imer Re: DEFRA Forschungsprojekt über Festlegungstechniken für Industriegeräusche In England ist Defra, das Ministerium für Umwelt, Nahrungsmittel und Landesaffairen für den Schutz und die Verbesserung der Umwelt und die Integration dieser Themen mit anderen der Regierung und auch international verantwortlich. In Folge des Defra Konsultationsreferats “Für eine Nationale Umgebungsgeräuschstrategie”, das im November 2001 veröffentlicht wurde, hat die Regierung ihre Absicht bekanntgegeben, bei der Entwicklung einer nationalen Umgebungsgeräuschstrategie in England Fortschritte zu machen. Phase 1 der Strategie ist das Festlegen der Hauptquellen und -geräuschbereiche, um das Umgebungsgeräuschklima in England festzustellen. Dies wird die Anzahl der Personen, die von verschiedenen Geräuschstufen betroffen sind, die Quelle dieses Geräuschs (Strassen, Zugschienen, Flughäfen und Industrie) und den Standort der betroffenen Personen feststellen. Diese Arbeit dient auch dazu, die anfänglichen Anforderungen der Europäischen Geräuschdirektive 2002/49/EC zu erfüllen. Obwohl es in England festgelegte Methoden im Bezug auf Strassen-, Schienen- und Flugzeuggeräusche gibt, gibt es im Gegensatz dazu keine ähnlichen standardisierten Methoden zur Feststellung von Geräuschen mit Ursprung in der Industrie. Defra hat daher Bureau Veritas Accoustic Technology damit beauftragt, die Rentabilität einer Darstellung der industriellen Geräuschquellen mit einer strategischen Geräuschfestlegung unter Verwendung einer Methodologie, die einfach, nachvollziehbar und robust ist, zu untersuchen. Aufgrund dieses Projekts kontaktieren wir die relevanten Regierungsabteilungen von ausgewählten anderen europäischen Ländern, um festzustellen, welche ähnliche Arbeiten unternommen worden sind oder gegenwärtig ausgeführt werden. Wir wären Ihnen daher dankbar, wenn Sie uns die Einzelheiten der Methodologien zur Feststellung der Geräuschstärkenstufe der industriellen Geräuschquellen im Bezug auf strategische Geräuschauslegung, die in Ihrem Land angewendet werden, mitteilen könnten. Wir sind an Techniken, die auf Messungen oder nicht-akustischen Methoden (z.B. Prozessinformation, Stromverbrauch, etc.) beruhen, interessiert. Gleichermassen wären wir Ihnen dankbar, wenn Sie uns über alle aktuellen Forschungen, die sich auf die Bestimmung der Geräuschstärkenstufen von industriellen Geräuschquellen zur Geräuschauslegung beziehen, informieren könnten. Sie können das Projektteam telefonisch, mit Fax oder Brief und unter den folgenden Email-Adressen kontaktieren: [email protected], [email protected], [email protected].

-2- Unsere Ref: AT5414/AMR/23665 1st April 2003 Wenn Sie der Meinung sind, dass es in Ihrer Abteilung eine weitere Person gibt, die zusätzlich oder anstelle von Ihnen kontaktiert werden sollte, dann geben Sie diesen Brief bitte weiter oder schicken Sie uns deren Kontaktdetails zu. Vielen Dank für Ihr Interesse und Zusammenarbeit. Mit freundlichen Grüssen BV ACOUSTIC TECHNOLOGY Bernard Postlethwaite Hauptberater

APPENDIX 4

List of Local Authorities who Responded to Questionnaire


AT 5414/2 Rev 1

Local Authority Respondents

Authority Adur District Council Allerdale Borough Council (Incl. Workington PHA) Alnwick D.C. Amber Valley Arun DC Babergh Barnsley Basildon Basingstoke & Deane Bath & North East Somerset Berwick-upon-Tweed Birmingham City Council Boston Borough Council Bournemouth Borough Council Bracknell Forest Borough Council Braintree Brentwood Brighton & Hove Bristol City UA Broadland Bromsgrove Broxbourne Broxtowe Borough Council Bury Cambridge City Council Cannock Chase Canterbury Carlisle City Council Castle Point Borough Council Charnwood Chelmsford Borough Council Chester City Council Chesterfield Chichester Christchurch City of Salford Congleton Borough Council Copeland Corby Borough Council Coventry Croydon Darlington

AT 5414/2 Rev 1

Authority Dartford Borough Council Derbyshire Dales Dudley MBC Easington East Cambridgeshire D.C. East Hampshire East Hertfordshire East Northamptonshire Council East Staffordshire Borough Council Eastleigh Borough Council Elmbridge Enfield Epsom & Ewell Borough Council Exeter Falmouth & Truro PHA Fareham Borough Council Fowey PHA Gateshead Council Guildford Halton Borough Council Harrogate Hart D.C. Hartlepool B.C. Hertsmere B.C. Hinckley & Bosworth B.C. Hull & Goole PHA Ipswich Isle of Wight / Medina Kennet Kensington & Chelsea Kirklees L.B. Brent L.B. of Sutton Lancaster City Council Leicester City Council Lincoln City Council Liverpool City Council London Borough of Ealing London Borough of Southwark London Borough of Waltham Forest London PHA Maldon D.C. Malvern Hills Manchester Mid Devon

AT 5414/2 Rev 1

Authority Mid Suffolk D.C. Mid Sussex District Council Newcastle upon Tyne Newham North Devon North Dorset D.C. North East Lincolnshire North Herts D.C. North Lincolnshire Council North Norfolk District Council Nottingham City Nuneaton & Bedworth BC Oadby & Wigston B.C. Oldham Oxford City Pendle Penwith Peterborough City Council Portsmouth City Council Reading D.C. Reigate & Banstead Restormel Ribble Valley River Blyth PHA River Tees PHA Rotherham Ryedale Sandwell Scarborough Sedgefield Borough Council Sevenoaks District Council Sheffield Slough Borough Council Solihull South Bucks South Derbyshire South Gloucestershire Council South Kesteven South Lakeland South Norfolk Council South Northamptonshire South Oxfordshire District Council South Ribble B.C. South Shropshire Southampton

AT 5414/2 Rev 1

Authority St Edmundsbury Stafford Stockport MBC Stroud Swansea Bay Port Health Authority Tameside M.B.C. Tandridge District Council Teesdale D.C. Tendring Tonbridge & Malling Borough Council Torbay Trafford MBC Tynedale DC Uttlesford Vale of White Horse District Council Vale Royal Borough Council Wansbeck Warrington Warwick Watford Council Waveney Wellingborough West Berkshire Council West Devon West Oxfordshire West Somerset Weymouth & Portland Borough Council Wigan Winchester Windsor & Maidenhead Wirral Worthing BC Wychavon York City UA

APPENDIX 5

Review of National Databases


REVIEW OF NATIONAL DATABASES

1. Introduction

A review of national databases has been undertaken for this project. The types of database that have

been reviewed are GIS databases, building height databases, population density and housing

databases.

The inclusion of industrial noise within the national noise-mapping programme will rely on the use of

appropriate datasets. These datasets will need to meet certain criteria and have known

characteristics to effectively integrate into any consistent process or procedure. The integration of

industrial sector noise levels will essentially require similar geo-referenced and attributed datasets for

input into the key noise modelling packages.

In the Birmingham noise-mapping programme the integration of industrial noise was handled very

simply. The results of the Birmingham study are now, however, largely outdated (at least in terms of

geospatial base datasets). In particular, the Ordnance Survey National Topographic Database has

replaced what was described in the Birmingham study and fulfils the gaps identified within the study.

Other datasets now allow a greater level of attribution and classification of the geospatial data, which

helps use the spatial data in a more intelligent fashion.

However, the datasets to be used for noise mapping have rarely been specifically created for this

process. This suggests that some pre-processing may be required to bring these datasets to an

appropriate scale, resolution or level of generalisation and format suitable for noise modelling

applications. It is also evident that a number of datasets may be essentially local or regional rather

than nationally consistent geospatial data. The approach to sourcing industrial layers within the

mapping may therefore need to be flexible in order to integrate data of varying formats into the

modelling process.

2. Data Specification

The specification for datasets is described below. The key data characteristics are:

Location (geographical position);

Classification (industrial, manufacturing or infrastructure);

Configuration (spatial arrangement, extent and height).


Taking these divisions further the datasets will ideally need to:

Identify industrial locations;

Classify the locations by industrial sector;

Identify the extent of the industrial sites as opposed to just the buildings at a site (for example

with quarry sites where the registered office may be remote from noise source);

Identify building (or noise source) configuration within a site;

Identify the building heights within the industrial location.

Whilst it may be simple to consider industrial site noise as something that can be described as a point

source this may not always be the case. Large industrial sites can have many processes, varying

levels of sound output from different parts of a site and multiple buildings with varied configurations.

3. Description of Datasets

3.1 General

The description of the datasets is divided into two sections, namely:

those that describe location and classification;

those that describe height.

3.2 Location and classification

Identifying the site of industrial processes and activities is a primary requirement. This involves three

separate elements; namely geographic position, extent and some way of classifying the industrial

activity. It is also realised that a single industrial site may encompass many sub-categories of building

including office space as well as processing plant with different noise output characteristics.

A number of potential sources of information have been identified that provide the location and

classification of industrial sectors.

Base data (OS Land-Line / OS MasterMap)

Points of Interest (PointX datasets)

Valuation office data

IPPC register data

Local Plan information – mineral and waste sites


Ordnance Survey Topographic Data:

Topographic data are used within the commercial residential, road, airport noise mapping to provide

feature data but can also be used to provide a source of industrial locations information. Generally,

the sites of industrial classes will have an addressable point file (building) and a boundary file for both

buildings on a site and any fenced or bounded area.

There are two National Topographic Database (NTD) derived datasets from Ordnance Survey that

fulfil part of this requirement, OS Land-LineTM and OS MasterMapTM. Both products are derived from

the National Topographic Database, the highest resolution standard database from the Ordnance

Survey. Land-Line is a vector-based product that represents mapped features by a series of lines.

These lines are not joined to create an area file that describes the land parcels. OS MasterMap is an

object-oriented database that records the attributes and the spatial data within a database. The OS

MasterMap information is referenced to a unique TOID (Topographic Identifier) that uniquely identifies

mapped features.

From a data processing standpoint the area based MasterMap provides a useful data source as the

areas can be selected and attributed based on the TOID reference, making addition of attributes of

the sites straightforward. MasterMap records land cover classes against each polygon within the

dataset. These attributes are recorded in the Real World Object catalogue. Although industrial

sectors are not themselves recorded, a number of object classes are relevant. All individual buildings

or groups of buildings within a single property boundary have separate TOIDs and separate attributes

for buildings over 50 m2.

Advantages of MasterMap are that it is a nationally consistent dataset, provided in polygon format,

and with a series of relevant attributes that will contribute to the mapping process for both industrial

and other noise sources. The area based TOID reference for all polygons allows the buildings and

land adjoining an industrial site to be separately recorded and associated with the same industrial

classification information. It provides the basis for attributing with other information - such as building

height information.

MasterMap inherently includes descriptive groups (Buildings) that include a number of separate

descriptive (distinctive) names, including a number of industrial features and groups such as industrial

estates. Land-Line does not treat the attribution of features in the same way, although the textual

descriptions (part of the dataset) may be present (and have been used to build PointX – see below).

Within MasterMap the description of a site should be included once, whereas in Land-Line the


descriptive text may be recorded more than once across boundaries and map tile sheets,

necessitating data cleaning.

Despite their advantages both the MasterMap and Land-Line datasets are very large and may affect

processing times. These may prove unacceptable for the noise mapping software processing and

would need to be evaluated. Given that only a few of the features are needed from the OS datasets it

would be possible to extract only those layers needed in the processing and even to generalise the

dataset to enhance processing speeds. Pre-processing to attribute height data to building areas may

need to be accomplished prior to any generalisation.

PointX Datasets:

PointX datasets appear to offer the best options for the identification of geo-referenced digital

locations of industrial and manufacturing centres. PointX collates, georeferences and quality assures

datasets from a wide range of sources. Many of the datasets from which the information is drawn are

from addressable locations with validation and update based on telephone interviews used to provide

updates. Point X adds the geocoding, typically with the grid reference falling within the boundary of

the addressable building.

The two main sources of information for PointX industrial and manufacturing sites are from Thompson

Directories and from data extractions from OS Land-Line textual data, as follows:

Thompson Directories – locations of categories of industrial and manufacturing centres

broken down into 6 categories with 153 classes. Other categories may also be relevant, such

as public infrastructure including refuse disposal, sewage disposal, etc.

Land-Line – certain datasets are extracted by reference to the text data within the site (e.g.

quarries).

PointX currently do not use OS MasterMap, but rather use Land-Line to collect other information on

locations and categories. Often this is based on the selection of the OS Land-Line text attributes to

provide a location. However, text in OS Land-Line may repeat and these duplicates are removed to

provide a single reference location. However, Point X has generally included the TOID reference

within the point files so that the features can link direct to OS MasterMap. The choice of spatial

referencing system will depend on the availability of the basemapping data to the consultants

undertaking the noise mapping.

The industrial and manufacturing sector is divided into 153 classes covering 6 categories. The six

categories are:


1. Consumer products

2. Extractive industry

3. Farming

4. Foodstuffs

5. Industrial features

6. Industrial products

Key limitations of PointX appear to be:

The PointX data is a point georeference file (the point falls within the topographic feature

outline it describes). In order to utilise this information within noise mapping it is anticipated

that the feature area data would need to be attributed with the PointX class descriptors. This

is a relatively straightforward geoprocessing step but may need validation. Only processing

those relevant classes can reduce the processing requirements.

The point may in a few cases reference to the site office rather than the feature. Further

evaluation of how to represent the whole of an industrial site may therefore be required.

The point may not effectively represent the location of the noise source being based on the

addressable feature rather than the full site boundary. However, there is no specific dataset

that will address this issue without major validation and hence this is not an easily resolvable

issue that another data source could improve.

Other Industrial / Land Use Sector Data:

Other datasets identified that include industrial categories include:

Valuation Office rateable values

IPPC Public Registers

Both these datasets include industrial sector information. The Valuation Office records information on

the rateable value of all non-domestic property in England and Wales of which there are around 1.7

million records (hereditaments). There are four broad classes of record, of which ‘factory’ is the

relevant class for industrial categories, which range from small workshops to manufacturing units.

These rateable values are based primarily on floor space, but may include land without buildings. For

industrial units where the rateable value is not based on floor space (e.g. iron and steel plants,

chemical works, refineries) are classed as non-bulk. Both the bulk and non-bulk classes are

categorised with primary descriptions. The non-bulk classes comprise some 400,000 records.


The limitation of the Valuation Office rates data is the lack of georeferencing and attribution of the

areas covered by the hereditaments. Georeferencing of the information would be needed to attribute

the addressable object using a dataset such as OS AddressPoint to provide a point reference, which

might then be attributed to the feature (site) outline.

Integrated Pollution Prevention Control data is maintained by the Environment Agency under section

20 of the Environment Protection Act 1990. This register records information of prescribed industrial

processes. Information is maintained as a Public Register. This information only includes those

industries that discharge to water or air. It may indicate the registered office or principle place of

business rather than the details of the relevant site/s. Despite the limitations of the data

comprehensiveness, the register may be able to add further details to the PointX datasets. As with

the Valuation Office data there is no implicit georeference, which would need to be added to the

datasets.

Other local information may be available for industrial areas or for specific industrial sectors, such as

the mineral extraction industry through Local Mineral Plans. These plans are generally in paper

format and indicate the status of mineral extraction sites and their boundaries. This data may be

useful in adding specific dimensions to sites. Other Local Plan data will also usually indicate key

industrial land use and land use development zones in paper proposal map formats, although this

information may not be in digital format.

Environment Agency landfill sites are also maintained as a digital spatial dataset. This records the

status of the site and its licence conditions, although more details are held in paper records than in the

basic digital files. T he dataset covers England and Wales.

Datasets are being generated all the time and new datasets are planned that may change the

perspective of the value of the above datasets or introduce new datasets or data attributes that are

useful in the industrial and other noise mapping. For example, Ordnance Survey has announced its

intention to create a building height dataset (see below). Other potentially important datasets plans of

relevance (but not yet available) include the National Land Use Database (NLUD) Baseline data. This

development programme aims to produce a full attribution of OS MasterMap data from a range of

sources. Depending on the levels of attribution (categories and classes) of land use this dataset

could remove some of the implied processing steps suggested in combining OSMasterMap and

PointX codes.


3.3 Height Data

Building height data is generally more difficult to source, as was found within the Birmingham study.

Although datasets do exist they are often irregular and very localised in spatial coverage, or are

commercially or strategically confidential. The issue of industrial site building heights is the same as

for other buildings height information and thus the same datasets are generally more widely

applicable to noise mapping. As with the spatial extent datasets, any single industrial site may

comprise many terrain features and buildings of varying heights and hence the data are not specific to

the industrial description.

There are two broad approaches to mapping height.

direct measurement, or estimation of building height from local ground level

terrain mapping where the buildings are included within the terrain surface (digital surface

models or digital elevation model).

In terms of processing there are also two main approaches:

little or no processing where the height data is directly attributed to the building location (as an

attribute of a point or area feature)

geoprocessing of surface terrain data to attribute the building seed point with the height.

Processing with this type of data source will require averaging (or some other descriptive

statistic) of height values within a building footprint. The processing could be achieved with

MasterMap and a surface model and would subtract the general surface level to derive local

building heights.

A number potential datasets are available and are summarised in the table overleaf.


Dataset Description Relevance to Industrial Noise Mapping General height data (OS 1:10 k terrain)

1:10,000 OS LandForm Profile information.

Maps surface terrain to MOD. Does not create a surface model of the imposed features and therefore does not provide the basis for mapping building heights, only landform.

Lidar (general terrain heights or surface terrain) – coverage

Light Detection and Ranging. Principle suppliers in UK are Environment Agency and Infoterra / Merrett Survey Partnership. Airborne laser scanning system

Variable dataset based on flying heights that determine resolution. The data are georeferenced and provide a full surface model. Datasets are sporadic and EA coverage tends to focus around floodplain and coastal areas.

NextMap (coverage) NextMap is a national terrain data capture programme based on airborne Synthetic Aperture Radar. A number of products will be available including the first Digital Surface Model and a Digital Terrain dataset.

High-resolution datasets between 0.5 - 1m resolution and 2.5m horizontal accuracy. Not yet covering the UK (see map in appendix). Products provide ground model and surface height models from which building heights can be obtained. Although building footprints can also be derived through processing of these high-resolution data this is not required due to availability of accurate OS topographic maps.

Building specific heights sources

Local datasets describing building heights

Little information exists on these sources, and may have been derived in a number of ways. Often this is through stereo aerial photo measurements or through automated satellite image processing techniques. The resolution of these data is high especially from aerial photographic images.

Building specific heights sources

A number of suppliers offer a range of products with attributed building heights often derived from image processing. CR World Cities Revealed, Infoterra, GeoSense etc

Datasets such as a CR City Heights provide vector dataset comprising of building footprint, building height, road centreline, and road centreline height data and is accurate to within 0.5 metres (vertical). The data is derived from aerial photographs using photogrammetric techniques and is supplied in DXF format. Currently the only city available is 160sqkm of Central London but other cities are planned.

Ordnance Survey layer in MasterMap Prior Indicative Notice (PIN)

Ordnance Survey has announced that an enhancement to MasterMap will be the inclusion of building height data within a Prior Indicative Notice.

This dataset would provide the basis for direct attribution of building areas. OS have released a PIN to identify potential data suppliers for building height data for parts of three cities (Bristol, Christchurch, Plymouth) to +/- 10cm. No further processing would be needed of this dataset.

Deriving data from satellite images /aerial photos

Image processing companies (e.g. Infoterra, Geosense)

Remote sensing and photogrammetric techniques can be used to derive terrain datasets. Accuracy is to +/- 1m RMSE. These products generally include ground heights and heights of other surface features. These products are often bespoke to customers’ requirements, or specific locations.

Summary of Building Height Data Sources


3.4 Population Data

The key source of population data is the decennial Census. The most recent census was undertaken

in 2001. The major difference of the 2001 census over previous censuses is that the information will

be largely freely available for download from the ONS website.

The development of noise mapping from industrial sources will need two specific elements for

geographical population estimates.

i) The local area statistics (the highest spatial resolution available); and

ii) The geographic boundaries in digital format for integration into the GIS modelling

environment.

Digital Census Boundary Data

Although collected at the house level Census data is aggregated to larger geographic regions to

maintain anonymity of the respondents. It is this small spatial scale data that will be required for noise

mapping. In the 1991 Census the smallest geographic area for which statistics were made available

was the Enumeration District (ED). The ED was essentially the area of equal workload for

enumerators and was developed by hand and these same areas provided the smallest data output

area.

A new approach has been adopted for the output of the Census 2001 creating a new small area

statistics output that does not relate to the enumerator effort area. The procedure / geographical

framework for these Output Areas (OA) is as follows:

postcode based building bricks, nesting within up to date '2003' ward and parish boundaries

created in an automatic process, using 1 metre co-ordinate referenced Census records and

other boundary and map information, in which

- polygons are created around every address

- these are grouped to form unit postcode polygons

- the postcodes are zoned into Output Areas using objective and systematic statistical

criteria


the process delivers

- consistently sized areas

- boundaries for GIS and electronic media

- look up tables for postcode links to non-Census data

- population weighted centroids and area measurements

The 2001 census has used automatically generated OA’s based on a set of consistently applied

criteria that enable better matching to postcode geography and to a more consistent population

estimate.

Thus, the Output Area for the 2001 census replaces the ED. The vector boundaries for the 175,434

Output Areas in England and Wales are available without charge from Census Customer Services.

Data is available in the following formats:

Boundaries for the whole of England and Wales, available as a shape file on two CDs and in

MID/MIF format on a DVD.

Whole of England and Wales, arranged for those who wish to extract and set up the

boundaries for a single local authority or a few authorities, available as a shape file on a DVD

or in MID/MIF format on a DVD.

All files contain vector boundaries, unique identifiers for OA’s, population weighted and geometric

centroids for OA’s, and area measurements for OA’s, together with a look-up table of OA’s by unit

postcodes.

Dwelling numbers Within the scope of the industrial noise mapping is the requirement to intersect the noise contours

with the number of dwellings affected. This requires a spatial dataset of dwellings. The key sources

of property boundaries data are from the Ordnance Survey topographic database, although there are

a number of other potential sources as point datasets. This data comes in a number of formats at the

highest resolution.

Ordnance Survey Land Line

Ordnance Survey MasterMap

AddressPoint.


These data sources are regularly updated with semi-continuous update of the OS topographic

database.

The Census also asks questions about the household as a whole relating to the dwelling, rooms,

tenure, amenities and the nature of the accommodation and sharing. This data also covers mobile

and temporary structures that often the OS datasets will not cover. However highest resolution data

for these results of these data are reported at the ED or OA level.

Key issues in establishing the dwelling numbers within a zone of influence are that not all building

locations or addressable objects represent a single dwelling and that not all accommodation is

reported or recorded with geographic co-ordinates. Blocks of flats and more recently divided houses

imply a greater population or larger number of individuals or groups living independently.

Land-Line is a vector based dataset that describes the boundary of the building footprint. However,

unlike MasterMap, the line-work is not polygonised and does not form a discrete object with a single

reference. In the case of MasterMap the Building outline is uniquely identified feature with a

topographic identifier, a TOID.

Neither Land-Line nor MasterMap distinguish part of buildings or dwellings; e.g. it would not

distinguish a ground floor shop from an upstairs dwelling or a set of flats from a single house.

In order to get this level of detail it is necessary to source additional address datasets.

Whilst there are some issues with the classification of items within OS AddressPoint data, it fulfils

most of the requirements of identifying independently addressable items. The profile of the product is

summarised in the table below. There are some items that are addressable but which are not

dwellings and these would need to be filtered before analysis of dwellings.


Specification ADDRESS-POINT

Data source Ordnance Survey database and Royal Mail’s Postcode Address File (PAF)

Addresses in series Approx 26 million Standard delivery units Government office region (eleven regions constitute

national cover). Availability National coverage (Great Britain) Coordinate resolution Normally 0.1m Data structure Attributed point Transfer format Comma separated values (CSV) Storage volumes Average record length per address:

150 bytes Supply media CD-ROM Update interval 3 months

AddressPoint data consists of the Royal Mail's Postcode Address Files (PAF) with the addition of

Ordnance Survey national grid information, AddressPoint unique reference point (OSAPR) and a

status flag to define the quality and accuracy of each address, AddressPoint also covers businesses

and these would need to be excluded from any assessment of dwellings – although they may still be

considered receiving environments in their own right.

OS is also creating and maintaining a National Buildings Data Set. This data set is an index of all

buildings. It consists of a core referencing module containing:

a unique topographic identifier for each building

with associated referencing into the existing Ordnance Survey product ADDRESS-POINT via

the OS Address Point Reference number; which can be made available with:

national grid co-ordinates, and

postal addresses (where they are available)

The definition of a building is “roofed constructions, usually walled”. This includes permanent roofed

constructions that exceed 8.0 m2 in area (12 m2 in private gardens). Exceptions are made for smaller

buildings in such a detached position that they form relatively important topographical features.

Mobile homes, residential caravans and so on are not captured. Storage tanks may be classified as

buildings.

There are other commercial products that can be used to identify postal addresses with additional

features and attributes, e.g. QuickAddress Business Pro, which reports at postcode level. This

product combines the functionality of QuickAddress Pro with business data from D&B. This enables

identification of business address and a unique D-U-N-S Number. The stated inputs to Quick Address

are 95% of the GDP for businesses and is updated quarterly.


D-U-N-S Numbers - The D-U-N-S Number is a nine-digit number that uniquely identifies each

business record within the UK Marketing File. The numbering structure links parent and subsidiary

companies, as well as head offices and branches. In addition the SIC codes can be supplied with the

datasets (SIC codes). Standard Industrial Classification (SIC) codes - These codes are used to

classify businesses by the activity they are involved in, and the type of products and services they

offer. The codes can be used to profile a database of customers or prospects. This has potential

both to identify the industrial sector but also as a way of filtering business properties from other

properties.

Other commercial products that go some way to classifying buildings include Cities Revealed Building

Class datasets. These assign building classes to residential buildings based on age and structural

types and are output as GIS tables (MapInfo/ ESRI). Data is currently only available for London.

The Office of National Statistics (through the ODPM) is also developing data on empty homes at ward

level as part of the neighbourhood Statistics Service. Although currently planned at ward level it is

anticipated that this will be at a higher resolution later (ODPM Working Group on Local Government

Financial Statistics). This data is not currently available and data is drawn from national datasets

wherever possible. A dwelling stock database is being developed by the Valuation Office Agency, but

is not currently available. The principle is to develop approaches to integrating dispersed databases

to generate this information, which indicates the distributed nature of current information describing

dwellings.

Local Council Tax records provide a source of information on occupancy and provide further

information on the valuation and whether the property is only partly used as a dwelling. The Valuation

Office maintains a consolidated central database of ratings. The national access to this database

would require negotiation with the Valuation Office. A number of classes of property and occupancies

are exempt from Council Tax but this is applied at local authority level so the national data hold all

rated properties and update this data for new buildings and modifications. These data are referenced

to the address and, in order to spatially sample beyond the postcode level, would require linking to a

product such as OS AddressPoint to allow intersection with the noise output levels.


APPENDIX 6

Results of Relative Humidity and Temperature Review Calculations


2 m Receiver Height

Distance Ground Temp RH SPL Deviation Distance Ground Temp RH SPL Deviation Distance Ground Temp RH SPL Deviationm Type oC % dB(A) dB m Type oC % dB(A) dB m Type oC % dB(A) dB

Flat Spectrum Shape Industrial Spectrum Shape Humped Spectrum Shape500 Hard -10 50 51.9 -3.5 500 Hard -10 50 56.6 -1.8 500 Hard -10 50 55.3 -2.6500 Hard -10 70 52.9 -2.6 500 Hard -10 70 57.3 -1.2 500 Hard -10 70 56.2 -1.6500 Hard -10 100 54.1 -1.4 500 Hard -10 100 57.9 -0.5 500 Hard -10 100 57.1 -0.7500 Hard 0 50 53.6 -1.9 500 Hard 0 50 57.6 -0.8 500 Hard 0 50 56.8 -1.1500 Hard 0 70 54.6 -0.9 500 Hard 0 70 58.1 -0.3 500 Hard 0 70 57.4 -0.4500 Hard 0 100 55.5 0.0 500 Hard 0 100 58.5 0.1 500 Hard 0 100 58.0 0.1500 Hard 10 50 54.9 -0.6 500 Hard 10 50 58.2 -0.2 500 Hard 10 50 57.6 -0.3500 Hard 10 70 55.5 500 Hard 10 70 58.4 500 Hard 10 70 57.9500 Hard 10 100 55.9 0.4 500 Hard 10 100 58.6 0.1 500 Hard 10 100 58.0 0.2500 Hard 20 50 55.2 -0.3 500 Hard 20 50 58.1 -0.3 500 Hard 20 50 57.5 -0.4500 Hard 20 70 55.4 -0.1 500 Hard 20 70 58.2 -0.3 500 Hard 20 70 57.5 -0.4500 Hard 20 100 55.4 -0.1 500 Hard 20 100 58.1 -0.3 500 Hard 20 100 57.5 -0.4500 Hard 35 50 54.0 -1.5 500 Hard 35 50 57.4 -1.0 500 Hard 35 50 56.4 -1.4500 Hard 35 70 53.9 -1.6 500 Hard 35 70 57.5 -0.9 500 Hard 35 70 56.5 -1.3500 Hard 35 100 54.1 -1.4 500 Hard 35 100 57.7 -0.7 500 Hard 35 100 56.9 -1.0500 Soft -10 50 44.0 -4.9 500 Soft -10 50 49.7 -2.1 500 Soft -10 50 46.8 -3.8500 Soft -10 70 45.3 -3.6 500 Soft -10 70 50.3 -1.5 500 Soft -10 70 48.0 -2.5500 Soft -10 100 46.9 -2.1 500 Soft -10 100 51.0 -0.8 500 Soft -10 100 49.2 -1.3500 Soft 0 50 46.4 -2.6 500 Soft 0 50 50.7 -1.0 500 Soft 0 50 48.9 -1.7500 Soft 0 70 47.7 -1.2 500 Soft 0 70 51.4 -0.4 500 Soft 0 70 49.9 -0.7500 Soft 0 100 48.8 -0.1 500 Soft 0 100 51.8 0.0 500 Soft 0 100 50.6 0.0500 Soft 10 50 48.2 -0.8 500 Soft 10 50 51.5 -0.3 500 Soft 10 50 50.1 -0.4500 Soft 10 70 48.9 500 Soft 10 70 51.8 500 Soft 10 70 50.6500 Soft 10 100 49.5 0.5 500 Soft 10 100 51.9 0.1 500 Soft 10 100 50.8 0.3500 Soft 20 50 48.7 -0.3 500 Soft 20 50 51.5 -0.3 500 Soft 20 50 50.2 -0.4500 Soft 20 70 48.9 0.0 500 Soft 20 70 51.6 -0.2 500 Soft 20 70 50.2 -0.3500 Soft 20 100 49.0 0.0 500 Soft 20 100 51.5 -0.3 500 Soft 20 100 50.2 -0.4500 Soft 35 50 47.1 -1.8 500 Soft 35 50 50.7 -1.1 500 Soft 35 50 48.7 -1.8500 Soft 35 70 46.9 -2.0 500 Soft 35 70 50.6 -1.2 500 Soft 35 70 48.7 -1.8500 Soft 35 100 47.0 -1.9 500 Soft 35 100 50.8 -1.0 500 Soft 35 100 49.0 -1.6

1000 Hard -10 50 43.4 -4.4 1000 Hard -10 50 49.4 -2.2 1000 Hard -10 50 47.1 -3.61000 Hard -10 70 44.9 -2.9 1000 Hard -10 70 50.2 -1.3 1000 Hard -10 70 48.6 -2.11000 Hard -10 100 46.3 -1.4 1000 Hard -10 100 51.1 -0.5 1000 Hard -10 100 49.8 -0.81000 Hard 0 50 45.9 -1.9 1000 Hard 0 50 50.8 -0.8 1000 Hard 0 50 49.4 -1.21000 Hard 0 70 47.0 -0.8 1000 Hard 0 70 51.4 -0.2 1000 Hard 0 70 50.3 -0.31000 Hard 0 100 47.9 0.2 1000 Hard 0 100 51.8 0.3 1000 Hard 0 100 51.0 0.31000 Hard 10 50 47.1 -0.6 1000 Hard 10 50 51.3 -0.3 1000 Hard 10 50 50.3 -0.31000 Hard 10 70 47.7 1000 Hard 10 70 51.6 1000 Hard 10 70 50.61000 Hard 10 100 48.1 0.3 1000 Hard 10 100 51.7 0.1 1000 Hard 10 100 50.7 0.11000 Hard 20 50 47.0 -0.7 1000 Hard 20 50 51.0 -0.6 1000 Hard 20 50 49.8 -0.81000 Hard 20 70 47.1 -0.7 1000 Hard 20 70 51.0 -0.6 1000 Hard 20 70 49.8 -0.81000 Hard 20 100 47.0 -0.7 1000 Hard 20 100 51.0 -0.6 1000 Hard 20 100 49.8 -0.91000 Hard 35 50 44.9 -2.8 1000 Hard 35 50 50.0 -1.6 1000 Hard 35 50 48.1 -2.51000 Hard 35 70 45.2 -2.5 1000 Hard 35 70 50.3 -1.3 1000 Hard 35 70 48.6 -2.01000 Hard 35 100 45.8 -2.0 1000 Hard 35 100 50.7 -0.9 1000 Hard 35 100 49.2 -1.41000 Soft -10 50 33.4 -6.9 1000 Soft -10 50 42.3 -2.3 1000 Soft -10 50 37.0 -5.61000 Soft -10 70 35.7 -4.7 1000 Soft -10 70 42.9 -1.7 1000 Soft -10 70 39.0 -3.51000 Soft -10 100 38.0 -2.3 1000 Soft -10 100 43.8 -0.8 1000 Soft -10 100 41.0 -1.51000 Soft 0 50 37.2 -3.1 1000 Soft 0 50 43.4 -1.2 1000 Soft 0 50 40.3 -2.21000 Soft 0 70 39.0 -1.4 1000 Soft 0 70 44.1 -0.5 1000 Soft 0 70 41.8 -0.81000 Soft 0 100 40.4 0.1 1000 Soft 0 100 44.7 0.1 1000 Soft 0 100 42.8 0.21000 Soft 10 50 39.4 -0.9 1000 Soft 10 50 44.3 -0.4 1000 Soft 10 50 42.0 -0.61000 Soft 10 70 40.3 1000 Soft 10 70 44.6 1000 Soft 10 70 42.51000 Soft 10 100 40.9 0.5 1000 Soft 10 100 44.7 0.1 1000 Soft 10 100 42.8 0.31000 Soft 20 50 39.6 -0.8 1000 Soft 20 50 44.2 -0.5 1000 Soft 20 50 41.7 -0.81000 Soft 20 70 39.6 -0.7 1000 Soft 20 70 44.1 -0.5 1000 Soft 20 70 41.6 -0.91000 Soft 20 100 39.4 -0.9 1000 Soft 20 100 44.0 -0.6 1000 Soft 20 100 41.4 -1.11000 Soft 35 50 36.5 -3.8 1000 Soft 35 50 43.0 -1.6 1000 Soft 35 50 39.1 -3.51000 Soft 35 70 36.6 -3.8 1000 Soft 35 70 43.1 -1.5 1000 Soft 35 70 39.4 -3.11000 Soft 35 100 37.1 -3.2 1000 Soft 35 100 43.4 -1.2 1000 Soft 35 100 40.1 -2.42000 Hard -10 50 34.3 -4.6 2000 Hard -10 50 41.8 -2.1 2000 Hard -10 50 37.6 -4.62000 Hard -10 70 36.2 -2.7 2000 Hard -10 70 42.8 -1.1 2000 Hard -10 70 39.9 -2.32000 Hard -10 100 38.0 -0.9 2000 Hard -10 100 43.7 -0.2 2000 Hard -10 100 41.8 -0.52000 Hard 0 50 37.2 -1.7 2000 Hard 0 50 43.2 -0.7 2000 Hard 0 50 41.0 -1.22000 Hard 0 70 38.6 -0.3 2000 Hard 0 70 43.9 0.0 2000 Hard 0 70 42.2 0.02000 Hard 0 100 39.6 0.7 2000 Hard 0 100 44.4 0.5 2000 Hard 0 100 43.0 0.82000 Hard 10 50 38.4 -0.5 2000 Hard 10 50 43.6 -0.3 2000 Hard 10 50 41.9 -0.32000 Hard 10 70 38.9 2000 Hard 10 70 43.9 2000 Hard 10 70 42.22000 Hard 10 100 39.1 0.2 2000 Hard 10 100 44.0 0.1 2000 Hard 10 100 42.2 0.02000 Hard 20 50 37.5 -1.4 2000 Hard 20 50 43.0 -0.9 2000 Hard 20 50 40.7 -1.52000 Hard 20 70 37.4 -1.5 2000 Hard 20 70 43.0 -0.9 2000 Hard 20 70 40.5 -1.72000 Hard 20 100 37.4 -1.5 2000 Hard 20 100 43.2 -0.7 2000 Hard 20 100 40.7 -1.62000 Hard 35 50 35.2 -3.7 2000 Hard 35 50 42.2 -1.7 2000 Hard 35 50 38.5 -3.82000 Hard 35 70 35.9 -3.0 2000 Hard 35 70 42.7 -1.2 2000 Hard 35 70 39.5 -2.82000 Hard 35 100 37.0 -1.9 2000 Hard 35 100 43.3 -0.6 2000 Hard 35 100 40.7 -1.62000 Soft -10 50 22.6 -7.8 2000 Soft -10 50 35.5 -1.6 2000 Soft -10 50 26.1 -7.12000 Soft -10 70 25.3 -5.2 2000 Soft -10 70 35.9 -1.2 2000 Soft -10 70 29.1 -4.12000 Soft -10 100 28.1 -2.4 2000 Soft -10 100 36.5 -0.6 2000 Soft -10 100 31.6 -1.62000 Soft 0 50 27.0 -3.4 2000 Soft 0 50 36.2 -0.9 2000 Soft 0 50 30.7 -2.52000 Soft 0 70 29.4 -1.1 2000 Soft 0 70 36.8 -0.3 2000 Soft 0 70 32.7 -0.62000 Soft 0 100 31.0 0.6 2000 Soft 0 100 37.4 0.3 2000 Soft 0 100 34.0 0.72000 Soft 10 50 29.6 -0.9 2000 Soft 10 50 36.8 -0.3 2000 Soft 10 50 32.6 -0.62000 Soft 10 70 30.5 2000 Soft 10 70 37.1 2000 Soft 10 70 33.22000 Soft 10 100 30.9 0.4 2000 Soft 10 100 37.2 0.1 2000 Soft 10 100 33.4 0.22000 Soft 20 50 28.8 -1.7 2000 Soft 20 50 36.5 -0.6 2000 Soft 20 50 31.5 -1.72000 Soft 20 70 28.6 -1.9 2000 Soft 20 70 36.5 -0.6 2000 Soft 20 70 31.3 -2.02000 Soft 20 100 28.2 -2.2 2000 Soft 20 100 36.4 -0.6 2000 Soft 20 100 31.0 -2.22000 Soft 35 50 24.6 -5.9 2000 Soft 35 50 35.8 -1.3 2000 Soft 35 50 27.8 -5.52000 Soft 35 70 25.3 -5.2 2000 Soft 35 70 36.0 -1.1 2000 Soft 35 70 28.8 -4.42000 Soft 35 100 26.6 -3.9 2000 Soft 35 100 36.3 -0.8 2000 Soft 35 100 30.2 -3.0

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AT5414/2 Rev 1 TABLE A6.1

Distance Rec Height Ground Temp RH SPL Deviation Distance Ground Temp RH SPL Deviationm m Type oC % dB(A) dB m Type oC % dB(A) dB

Sloped UP Spectrum Shape Sloped DOWN Spectrum Shape500 2 Hard -10 50 45.8 -5.4 500 Hard -10 50 56.4 -1.8500 2 Hard -10 70 46.8 -4.4 500 Hard -10 70 57.1 -1.2500 2 Hard -10 100 48.5 -2.7 500 Hard -10 100 57.8 -0.5500 2 Hard 0 50 47.8 -3.4 500 Hard 0 50 57.5 -0.8500 2 Hard 0 70 49.4 -1.7 500 Hard 0 70 58.0 -0.3500 2 Hard 0 100 50.9 -0.3 500 Hard 0 100 58.4 0.1500 2 Hard 10 50 50.0 -1.1 500 Hard 10 50 58.0 -0.2500 2 Hard 10 70 51.2 500 Hard 10 70 58.3500 2 Hard 10 100 52.1 0.9 500 Hard 10 100 58.4 0.1500 2 Hard 20 50 51.0 -0.1 500 Hard 20 50 58.0 -0.3500 2 Hard 20 70 51.6 0.4 500 Hard 20 70 58.0 -0.3500 2 Hard 20 100 51.9 0.7 500 Hard 20 100 58.0 -0.3500 2 Hard 35 50 49.8 -1.4 500 Hard 35 50 57.2 -1.0500 2 Hard 35 70 49.5 -1.7 500 Hard 35 70 57.3 -0.9500 2 Hard 35 100 49.3 -1.9 500 Hard 35 100 57.6 -0.7500 2 Soft -10 50 39.1 -6.3 500 Soft -10 50 47.6 -2.9500 2 Soft -10 70 40.3 -5.1 500 Soft -10 70 48.5 -2.0500 2 Soft -10 100 42.2 -3.2 500 Soft -10 100 49.5 -1.1500 2 Soft 0 50 41.5 -3.9 500 Soft 0 50 49.2 -1.4500 2 Soft 0 70 43.4 -2.0 500 Soft 0 70 50.0 -0.6500 2 Soft 0 100 45.0 -0.4 500 Soft 0 100 50.6 0.0500 2 Soft 10 50 44.2 -1.2 500 Soft 10 50 50.2 -0.4500 2 Soft 10 70 45.4 500 Soft 10 70 50.5500 2 Soft 10 100 46.4 1.0 500 Soft 10 100 50.8 0.2500 2 Soft 20 50 45.3 -0.1 500 Soft 20 50 50.2 -0.3500 2 Soft 20 70 46.0 0.6 500 Soft 20 70 50.3 -0.3500 2 Soft 20 100 46.3 0.9 500 Soft 20 100 50.2 -0.3500 2 Soft 35 50 43.9 -1.5 500 Soft 35 50 49.1 -1.5500 2 Soft 35 70 43.6 -1.8 500 Soft 35 70 49.1 -1.5500 2 Soft 35 100 43.3 -2.1 500 Soft 35 100 49.3 -1.3

1000 2 Hard -10 50 35.4 -7.0 1000 Hard -10 50 49.1 -2.21000 2 Hard -10 70 37.5 -4.9 1000 Hard -10 70 50.0 -1.31000 2 Hard -10 100 39.7 -2.7 1000 Hard -10 100 50.9 -0.51000 2 Hard 0 50 39.0 -3.4 1000 Hard 0 50 50.6 -0.81000 2 Hard 0 70 40.7 -1.7 1000 Hard 0 70 51.2 -0.21000 2 Hard 0 100 42.3 0.0 1000 Hard 0 100 51.6 0.31000 2 Hard 10 50 41.2 -1.1 1000 Hard 10 50 51.1 -0.21000 2 Hard 10 70 42.4 1000 Hard 10 70 51.41000 2 Hard 10 100 43.2 0.8 1000 Hard 10 100 51.4 0.11000 2 Hard 20 50 41.7 -0.7 1000 Hard 20 50 50.7 -0.61000 2 Hard 20 70 42.0 -0.4 1000 Hard 20 70 50.8 -0.61000 2 Hard 20 100 42.0 -0.4 1000 Hard 20 100 50.8 -0.61000 2 Hard 35 50 38.7 -3.7 1000 Hard 35 50 49.7 -1.61000 2 Hard 35 70 38.7 -3.7 1000 Hard 35 70 50.1 -1.31000 2 Hard 35 100 39.1 -3.3 1000 Hard 35 100 50.5 -0.81000 2 Soft -10 50 26.7 -9.2 1000 Soft -10 50 39.1 -3.71000 2 Soft -10 70 29.5 -6.4 1000 Soft -10 70 40.3 -2.51000 2 Soft -10 100 32.4 -3.5 1000 Soft -10 100 41.7 -1.21000 2 Soft 0 50 31.4 -4.5 1000 Soft 0 50 41.2 -1.71000 2 Soft 0 70 33.7 -2.2 1000 Soft 0 70 42.2 -0.61000 2 Soft 0 100 35.7 -0.2 1000 Soft 0 100 43.0 0.21000 2 Soft 10 50 34.5 -1.4 1000 Soft 10 50 42.4 -0.51000 2 Soft 10 70 35.9 1000 Soft 10 70 42.81000 2 Soft 10 100 36.9 0.9 1000 Soft 10 100 43.0 0.21000 2 Soft 20 50 35.3 -0.6 1000 Soft 20 50 42.2 -0.71000 2 Soft 20 70 35.6 -0.3 1000 Soft 20 70 42.1 -0.71000 2 Soft 20 100 35.5 -0.4 1000 Soft 20 100 42.0 -0.81000 2 Soft 35 50 31.8 -4.2 1000 Soft 35 50 40.4 -2.51000 2 Soft 35 70 31.5 -4.5 1000 Soft 35 70 40.6 -2.21000 2 Soft 35 100 31.8 -4.2 1000 Soft 35 100 41.1 -1.82000 2 Hard -10 50 25.0 -7.4 2000 Hard -10 50 41.2 -2.42000 2 Hard -10 70 27.6 -4.8 2000 Hard -10 70 42.4 -1.12000 2 Hard -10 100 30.2 -2.2 2000 Hard -10 100 43.5 -0.12000 2 Hard 0 50 29.2 -3.2 2000 Hard 0 50 43.0 -0.62000 2 Hard 0 70 31.3 -1.1 2000 Hard 0 70 43.7 0.12000 2 Hard 0 100 32.9 0.5 2000 Hard 0 100 44.2 0.62000 2 Hard 10 50 31.4 -1.0 2000 Hard 10 50 43.3 -0.22000 2 Hard 10 70 32.4 2000 Hard 10 70 43.62000 2 Hard 10 100 32.9 0.6 2000 Hard 10 100 43.6 0.12000 2 Hard 20 50 30.8 -1.6 2000 Hard 20 50 42.5 -1.02000 2 Hard 20 70 30.7 -1.7 2000 Hard 20 70 42.6 -1.02000 2 Hard 20 100 30.4 -1.9 2000 Hard 20 100 42.8 -0.82000 2 Hard 35 50 26.7 -5.7 2000 Hard 35 50 41.6 -1.92000 2 Hard 35 70 27.5 -4.9 2000 Hard 35 70 42.2 -1.32000 2 Hard 35 100 28.7 -3.6 2000 Hard 35 100 43.0 -0.62000 2 Soft -10 50 13.8 -11.2 2000 Soft -10 50 31.2 -3.32000 2 Soft -10 70 17.5 -7.5 2000 Soft -10 70 32.2 -2.22000 2 Soft -10 100 21.4 -3.6 2000 Soft -10 100 33.5 -0.92000 2 Soft 0 50 20.1 -4.9 2000 Soft 0 50 32.9 -1.52000 2 Soft 0 70 23.2 -1.8 2000 Soft 0 70 34.0 -0.42000 2 Soft 0 100 25.5 0.4 2000 Soft 0 100 34.9 0.52000 2 Soft 10 50 23.7 -1.4 2000 Soft 10 50 34.0 -0.42000 2 Soft 10 70 25.1 2000 Soft 10 70 34.42000 2 Soft 10 100 25.9 0.8 2000 Soft 10 100 34.6 0.12000 2 Soft 20 50 23.4 -1.7 2000 Soft 20 50 33.4 -1.12000 2 Soft 20 70 23.3 -1.7 2000 Soft 20 70 33.3 -1.12000 2 Soft 20 100 22.8 -2.3 2000 Soft 20 100 33.2 -1.22000 2 Soft 35 50 17.4 -7.6 2000 Soft 35 50 31.8 -2.62000 2 Soft 35 70 18.0 -7.1 2000 Soft 35 70 32.2 -2.22000 2 Soft 35 100 19.4 -5.6 2000 Soft 35 100 32.9 -1.6


4 m Receiver Height

Distance Ground Temp RH SPL Deviation Distance Ground Temp RH SPL Deviation Distance Ground Temp RH SPL Deviationm Type oC % dB(A) dB m Type oC % dB(A) dB m Type oC % dB(A) dB

Flat Spectrum Shape Industrial Spectrum Shape Humped Spectrum Shape500 Hard -10 50 51.6 -3.6 500 Hard -10 50 56.2 -1.8 500 Hard -10 50 54.9 -2.6500 Hard -10 70 52.6 -2.5 500 Hard -10 70 56.9 -1.1 500 Hard -10 70 55.9 -1.6500 Hard -10 100 53.7 -1.4 500 Hard -10 100 57.5 -0.5 500 Hard -10 100 56.7 -0.8500 Hard 0 50 53.3 -1.8 500 Hard 0 50 57.3 -0.8 500 Hard 0 50 56.4 -1.1500 Hard 0 70 54.3 -0.8 500 Hard 0 70 57.8 -0.3 500 Hard 0 70 57.1 -0.4500 Hard 0 100 55.1 0.0 500 Hard 0 100 58.2 0.1 500 Hard 0 100 57.6 0.1500 Hard 10 50 54.5 -0.6 500 Hard 10 50 57.8 -0.3 500 Hard 10 50 57.2 -0.3500 Hard 10 70 55.1 500 Hard 10 70 58.1 500 Hard 10 70 57.5500 Hard 10 100 55.5 0.4 500 Hard 10 100 58.2 0.1 500 Hard 10 100 57.7 0.2500 Hard 20 50 54.8 -0.3 500 Hard 20 50 57.8 -0.3 500 Hard 20 50 57.1 -0.4500 Hard 20 70 55.0 -0.1 500 Hard 20 70 57.8 -0.3 500 Hard 20 70 57.2 -0.3500 Hard 20 100 55.1 0.0 500 Hard 20 100 57.8 -0.3 500 Hard 20 100 57.2 -0.3500 Hard 35 50 53.6 -1.5 500 Hard 35 50 57.0 -1.1 500 Hard 35 50 56.1 -1.4500 Hard 35 70 53.6 -1.6 500 Hard 35 70 57.1 -0.9 500 Hard 35 70 56.2 -1.3500 Hard 35 100 53.7 -1.4 500 Hard 35 100 57.4 -0.7 500 Hard 35 100 56.5 -1.0500 Soft -10 50 44.9 -4.4 500 Soft -10 50 50.1 -2.1 500 Soft -10 50 48.1 -3.3500 Soft -10 70 46.1 -3.2 500 Soft -10 70 50.8 -1.4 500 Soft -10 70 49.2 -2.2500 Soft -10 100 47.6 -1.8 500 Soft -10 100 51.5 -0.7 500 Soft -10 100 50.3 -1.0500 Soft 0 50 47.0 -2.3 500 Soft 0 50 51.3 -1.0 500 Soft 0 50 49.9 -1.4500 Soft 0 70 48.3 -1.1 500 Soft 0 70 51.8 -0.4 500 Soft 0 70 50.8 -0.6500 Soft 0 100 49.3 -0.1 500 Soft 0 100 52.2 0.0 500 Soft 0 100 51.4 0.0500 Soft 10 50 48.7 -0.7 500 Soft 10 50 52.0 -0.3 500 Soft 10 50 51.0 -0.4500 Soft 10 70 49.4 500 Soft 10 70 52.2 500 Soft 10 70 51.3500 Soft 10 100 49.8 0.5 500 Soft 10 100 52.3 0.1 500 Soft 10 100 51.5 0.2500 Soft 20 50 49.1 -0.3 500 Soft 20 50 51.9 -0.3 500 Soft 20 50 51.0 -0.4500 Soft 20 70 49.3 -0.1 500 Soft 20 70 51.9 -0.3 500 Soft 20 70 51.0 -0.4500 Soft 20 100 49.3 0.0 500 Soft 20 100 51.9 -0.3 500 Soft 20 100 50.9 -0.4500 Soft 35 50 47.6 -1.8 500 Soft 35 50 51.0 -1.2 500 Soft 35 50 49.7 -1.7500 Soft 35 70 47.5 -1.9 500 Soft 35 70 51.1 -1.1 500 Soft 35 70 49.7 -1.6500 Soft 35 100 47.6 -1.8 500 Soft 35 100 51.3 -0.9 500 Soft 35 100 50.0 -1.31000 Hard -10 50 43.2 -4.4 1000 Hard -10 50 49.2 -2.2 1000 Hard -10 50 46.9 -3.61000 Hard -10 70 44.7 -2.8 1000 Hard -10 70 50.1 -1.3 1000 Hard -10 70 48.4 -2.01000 Hard -10 100 46.2 -1.3 1000 Hard -10 100 50.9 -0.5 1000 Hard -10 100 49.7 -0.71000 Hard 0 50 45.7 -1.9 1000 Hard 0 50 50.6 -0.8 1000 Hard 0 50 49.2 -1.21000 Hard 0 70 46.8 -0.7 1000 Hard 0 70 51.2 -0.2 1000 Hard 0 70 50.2 -0.31000 Hard 0 100 47.7 0.2 1000 Hard 0 100 51.6 0.2 1000 Hard 0 100 50.8 0.31000 Hard 10 50 46.9 -0.6 1000 Hard 10 50 51.1 -0.3 1000 Hard 10 50 50.1 -0.31000 Hard 10 70 47.5 1000 Hard 10 70 51.4 1000 Hard 10 70 50.41000 Hard 10 100 47.9 0.4 1000 Hard 10 100 51.5 0.1 1000 Hard 10 100 50.6 0.11000 Hard 20 50 46.8 -0.7 1000 Hard 20 50 50.8 -0.6 1000 Hard 20 50 49.7 -0.81000 Hard 20 70 46.9 -0.7 1000 Hard 20 70 50.8 -0.6 1000 Hard 20 70 49.6 -0.81000 Hard 20 100 46.8 -0.7 1000 Hard 20 100 50.9 -0.5 1000 Hard 20 100 49.6 -0.81000 Hard 35 50 44.8 -2.8 1000 Hard 35 50 49.8 -1.6 1000 Hard 35 50 48.0 -2.51000 Hard 35 70 45.0 -2.5 1000 Hard 35 70 50.1 -1.3 1000 Hard 35 70 48.4 -2.01000 Hard 35 100 45.6 -2.0 1000 Hard 35 100 50.5 -0.9 1000 Hard 35 100 49.0 -1.41000 Soft -10 50 34.9 -6.0 1000 Soft -10 50 42.8 -2.3 1000 Soft -10 50 38.8 -4.71000 Soft -10 70 37.0 -3.9 1000 Soft -10 70 43.5 -1.6 1000 Soft -10 70 40.7 -2.81000 Soft -10 100 39.0 -2.0 1000 Soft -10 100 44.4 -0.7 1000 Soft -10 100 42.3 -1.21000 Soft 0 50 38.3 -2.6 1000 Soft 0 50 44.0 -1.1 1000 Soft 0 50 41.7 -1.71000 Soft 0 70 39.8 -1.1 1000 Soft 0 70 44.7 -0.4 1000 Soft 0 70 43.0 -0.51000 Soft 0 100 41.0 0.1 1000 Soft 0 100 45.3 0.2 1000 Soft 0 100 43.8 0.31000 Soft 10 50 40.1 -0.8 1000 Soft 10 50 44.8 -0.3 1000 Soft 10 50 43.0 -0.51000 Soft 10 70 40.9 1000 Soft 10 70 45.1 1000 Soft 10 70 43.51000 Soft 10 100 41.4 0.5 1000 Soft 10 100 45.2 0.1 1000 Soft 10 100 43.7 0.21000 Soft 20 50 40.2 -0.8 1000 Soft 20 50 44.6 -0.5 1000 Soft 20 50 42.7 -0.81000 Soft 20 70 40.2 -0.7 1000 Soft 20 70 44.5 -0.5 1000 Soft 20 70 42.6 -0.91000 Soft 20 100 40.1 -0.8 1000 Soft 20 100 44.5 -0.6 1000 Soft 20 100 42.5 -1.01000 Soft 35 50 37.4 -3.5 1000 Soft 35 50 43.5 -1.6 1000 Soft 35 50 40.4 -3.11000 Soft 35 70 37.6 -3.3 1000 Soft 35 70 43.6 -1.4 1000 Soft 35 70 40.8 -2.71000 Soft 35 100 38.2 -2.8 1000 Soft 35 100 44.0 -1.1 1000 Soft 35 100 41.5 -2.02000 Hard -10 50 34.2 -4.6 2000 Hard -10 50 41.7 -2.1 2000 Hard -10 50 37.5 -4.62000 Hard -10 70 36.1 -2.7 2000 Hard -10 70 42.7 -1.1 2000 Hard -10 70 39.9 -2.32000 Hard -10 100 37.9 -0.9 2000 Hard -10 100 43.6 -0.2 2000 Hard -10 100 41.7 -0.52000 Hard 0 50 37.1 -1.7 2000 Hard 0 50 43.1 -0.7 2000 Hard 0 50 40.9 -1.22000 Hard 0 70 38.5 -0.3 2000 Hard 0 70 43.8 0.0 2000 Hard 0 70 42.1 0.02000 Hard 0 100 39.5 0.7 2000 Hard 0 100 44.3 0.5 2000 Hard 0 100 42.9 0.82000 Hard 10 50 38.3 -0.5 2000 Hard 10 50 43.6 -0.2 2000 Hard 10 50 41.8 -0.32000 Hard 10 70 38.8 2000 Hard 10 70 43.8 2000 Hard 10 70 42.12000 Hard 10 100 39.0 0.2 2000 Hard 10 100 43.9 0.1 2000 Hard 10 100 42.1 0.02000 Hard 20 50 37.4 -1.4 2000 Hard 20 50 42.9 -0.9 2000 Hard 20 50 40.6 -1.52000 Hard 20 70 37.3 -1.5 2000 Hard 20 70 43.0 -0.8 2000 Hard 20 70 40.5 -1.62000 Hard 20 100 37.3 -1.5 2000 Hard 20 100 43.1 -0.7 2000 Hard 20 100 40.6 -1.52000 Hard 35 50 35.1 -3.7 2000 Hard 35 50 42.1 -1.7 2000 Hard 35 50 38.4 -3.82000 Hard 35 70 35.8 -3.0 2000 Hard 35 70 42.6 -1.2 2000 Hard 35 70 39.4 -2.82000 Hard 35 100 36.9 -1.9 2000 Hard 35 100 43.2 -0.6 2000 Hard 35 100 40.6 -1.52000 Soft -10 50 24.5 -6.8 2000 Soft -10 50 35.8 -1.8 2000 Soft -10 50 28.3 -6.22000 Soft -10 70 27.1 -4.3 2000 Soft -10 70 36.3 -1.2 2000 Soft -10 70 31.2 -3.32000 Soft -10 100 29.6 -1.8 2000 Soft -10 100 37.1 -0.5 2000 Soft -10 100 33.4 -1.12000 Soft 0 50 28.6 -2.8 2000 Soft 0 50 36.7 -0.9 2000 Soft 0 50 32.6 -1.92000 Soft 0 70 30.6 -0.8 2000 Soft 0 70 37.3 -0.2 2000 Soft 0 70 34.2 -0.32000 Soft 0 100 32.0 0.6 2000 Soft 0 100 37.9 0.4 2000 Soft 0 100 35.3 0.82000 Soft 10 50 30.6 -0.7 2000 Soft 10 50 37.3 -0.3 2000 Soft 10 50 34.1 -0.42000 Soft 10 70 31.4 2000 Soft 10 70 37.6 2000 Soft 10 70 34.52000 Soft 10 100 31.7 0.3 2000 Soft 10 100 37.7 0.1 2000 Soft 10 100 34.6 0.12000 Soft 20 50 29.7 -1.6 2000 Soft 20 50 36.9 -0.7 2000 Soft 20 50 32.8 -1.72000 Soft 20 70 29.5 -1.8 2000 Soft 20 70 36.9 -0.7 2000 Soft 20 70 32.6 -1.92000 Soft 20 100 29.3 -2.1 2000 Soft 20 100 36.9 -0.7 2000 Soft 20 100 32.5 -2.02000 Soft 35 50 26.1 -5.3 2000 Soft 35 50 36.1 -1.4 2000 Soft 35 50 29.7 -4.82000 Soft 35 70 26.9 -4.4 2000 Soft 35 70 36.4 -1.2 2000 Soft 35 70 30.8 -3.7


2000 Soft 35 100 28.2 -3.2 2000 Soft 35 100 36.8 -0.8 2000 Soft 35 100 32.1 -2.4

Cont/…


Distance Ground Temp RH SPL Deviation Distance Ground Temp RH SPL Deviationm Type oC % dB(A) dB m Type oC % dB(A) dB

Sloped UP Spectrum Shape Sloped DOWN Spectrum Shape500 Hard -10 50 45.4 -5.4 500 Hard -10 50 56.1 -1.9500 Hard -10 70 46.5 -4.3 500 Hard -10 70 56.8 -1.1500 Hard -10 100 48.1 -2.7 500 Hard -10 100 57.4 -0.5500 Hard 0 50 47.5 -3.3 500 Hard 0 50 57.1 -0.8500 Hard 0 70 49.1 -1.7 500 Hard 0 70 57.7 -0.3500 Hard 0 100 50.5 -0.3 500 Hard 0 100 58.0 0.1500 Hard 10 50 49.7 -1.1 500 Hard 10 50 57.7 -0.3500 Hard 10 70 50.8 500 Hard 10 70 57.9500 Hard 10 100 51.7 0.9 500 Hard 10 100 58.0 0.1500 Hard 20 50 50.7 -0.1 500 Hard 20 50 57.6 -0.3500 Hard 20 70 51.3 0.5 500 Hard 20 70 57.6 -0.3500 Hard 20 100 51.6 0.8 500 Hard 20 100 57.7 -0.2500 Hard 35 50 49.4 -1.4 500 Hard 35 50 56.8 -1.1500 Hard 35 70 49.1 -1.7 500 Hard 35 70 57.0 -0.9500 Hard 35 100 48.9 -1.9 500 Hard 35 100 57.2 -0.7500 Soft -10 50 39.7 -5.9 500 Soft -10 50 48.6 -2.6500 Soft -10 70 40.7 -4.8 500 Soft -10 70 49.5 -1.8500 Soft -10 100 42.6 -2.9 500 Soft -10 100 50.4 -0.9500 Soft 0 50 41.9 -3.7 500 Soft 0 50 50.1 -1.2500 Soft 0 70 43.7 -1.9 500 Soft 0 70 50.8 -0.5500 Soft 0 100 45.2 -0.3 500 Soft 0 100 51.3 0.0500 Soft 10 50 44.4 -1.2 500 Soft 10 50 50.9 -0.3500 Soft 10 70 45.6 500 Soft 10 70 51.3500 Soft 10 100 46.5 1.0 500 Soft 10 100 51.4 0.2500 Soft 20 50 45.4 -0.1 500 Soft 20 50 50.9 -0.3500 Soft 20 70 46.1 0.5 500 Soft 20 70 50.9 -0.3500 Soft 20 100 46.4 0.8 500 Soft 20 100 50.9 -0.3500 Soft 35 50 44.1 -1.5 500 Soft 35 50 49.9 -1.4500 Soft 35 70 43.8 -1.8 500 Soft 35 70 49.9 -1.3500 Soft 35 100 43.5 -2.0 500 Soft 35 100 50.2 -1.11000 Hard -10 50 35.2 -7.0 1000 Hard -10 50 48.9 -2.31000 Hard -10 70 37.4 -4.8 1000 Hard -10 70 49.9 -1.31000 Hard -10 100 39.5 -2.7 1000 Hard -10 100 50.8 -0.41000 Hard 0 50 38.8 -3.4 1000 Hard 0 50 50.4 -0.81000 Hard 0 70 40.6 -1.6 1000 Hard 0 70 51.0 -0.21000 Hard 0 100 42.1 -0.1 1000 Hard 0 100 51.4 0.31000 Hard 10 50 41.0 -1.2 1000 Hard 10 50 50.9 -0.31000 Hard 10 70 42.2 1000 Hard 10 70 51.21000 Hard 10 100 43.0 0.8 1000 Hard 10 100 51.3 0.11000 Hard 20 50 41.5 -0.7 1000 Hard 20 50 50.6 -0.61000 Hard 20 70 41.8 -0.4 1000 Hard 20 70 50.6 -0.61000 Hard 20 100 41.8 -0.4 1000 Hard 20 100 50.6 -0.51000 Hard 35 50 38.6 -3.6 1000 Hard 35 50 49.6 -1.61000 Hard 35 70 38.5 -3.7 1000 Hard 35 70 49.9 -1.31000 Hard 35 100 38.9 -3.3 1000 Hard 35 100 50.3 -0.81000 Soft -10 50 27.9 -8.4 1000 Soft -10 50 40.4 -3.31000 Soft -10 70 30.4 -5.8 1000 Soft -10 70 41.6 -2.11000 Soft -10 100 33.0 -3.2 1000 Soft -10 100 42.8 -0.91000 Soft 0 50 32.2 -4.1 1000 Soft 0 50 42.3 -1.31000 Soft 0 70 34.3 -1.9 1000 Soft 0 70 43.3 -0.41000 Soft 0 100 36.1 -0.1 1000 Soft 0 100 43.9 0.21000 Soft 10 50 34.9 -1.3 1000 Soft 10 50 43.3 -0.41000 Soft 10 70 36.2 1000 Soft 10 70 43.71000 Soft 10 100 37.1 0.9 1000 Soft 10 100 43.8 0.21000 Soft 20 50 35.6 -0.7 1000 Soft 20 50 43.0 -0.71000 Soft 20 70 35.9 -0.4 1000 Soft 20 70 43.0 -0.71000 Soft 20 100 35.8 -0.4 1000 Soft 20 100 42.9 -0.81000 Soft 35 50 32.3 -4.0 1000 Soft 35 50 41.4 -2.31000 Soft 35 70 32.0 -4.2 1000 Soft 35 70 41.7 -2.01000 Soft 35 100 32.4 -3.9 1000 Soft 35 100 42.2 -1.52000 Hard -10 50 24.9 -7.4 2000 Hard -10 50 41.1 -2.42000 Hard -10 70 27.5 -4.7 2000 Hard -10 70 42.3 -1.12000 Hard -10 100 30.1 -2.2 2000 Hard -10 100 43.4 0.02000 Hard 0 50 29.1 -3.2 2000 Hard 0 50 42.9 -0.62000 Hard 0 70 31.2 -1.1 2000 Hard 0 70 43.6 0.12000 Hard 0 100 32.8 0.5 2000 Hard 0 100 44.1 0.62000 Hard 10 50 31.3 -0.9 2000 Hard 10 50 43.3 -0.22000 Hard 10 70 32.3 2000 Hard 10 70 43.52000 Hard 10 100 32.8 0.6 2000 Hard 10 100 43.5 0.12000 Hard 20 50 30.7 -1.6 2000 Hard 20 50 42.4 -1.02000 Hard 20 70 30.6 -1.6 2000 Hard 20 70 42.5 -0.92000 Hard 20 100 30.3 -1.9 2000 Hard 20 100 42.7 -0.72000 Hard 35 50 26.6 -5.7 2000 Hard 35 50 41.5 -1.92000 Hard 35 70 27.4 -4.9 2000 Hard 35 70 42.1 -1.32000 Hard 35 100 28.7 -3.6 2000 Hard 35 100 42.9 -0.62000 Soft -10 50 15.9 -9.8 2000 Soft -10 50 32.2 -3.22000 Soft -10 70 19.2 -6.4 2000 Soft -10 70 33.4 -2.02000 Soft -10 100 22.6 -3.1 2000 Soft -10 100 34.8 -0.62000 Soft 0 50 21.4 -4.3 2000 Soft 0 50 34.2 -1.22000 Soft 0 70 24.1 -1.6 2000 Soft 0 70 35.2 -0.22000 Soft 0 100 26.1 0.4 2000 Soft 0 100 36.0 0.62000 Soft 10 50 24.4 -1.2 2000 Soft 10 50 35.1 -0.32000 Soft 10 70 25.6 2000 Soft 10 70 35.42000 Soft 10 100 26.3 0.7 2000 Soft 10 100 35.5 0.12000 Soft 20 50 23.9 -1.7 2000 Soft 20 50 34.3 -1.12000 Soft 20 70 23.8 -1.8 2000 Soft 20 70 34.2 -1.22000 Soft 20 100 23.4 -2.2 2000 Soft 20 100 34.2 -1.22000 Soft 35 50 18.7 -7.0 2000 Soft 35 50 32.8 -2.62000 Soft 35 70 19.4 -6.3 2000 Soft 35 70 33.3 -2.1


2000 Soft 35 100 20.8 -4.9 2000 Soft 35 100 34.1 -1.3


APPENDIX 7:

Noise Modelling Summary Sheets – Point Source


31.5 63 125 250 500 1k 2k 4k 8kCorrected for 500Hz

ground effects

FLAT SOUND POWER LEVEL SPECTRUM 120 113 113 113 113 113 113 113 113 113Sound Pressure Level:

Hard 2 50 2 77 71 71 71 71 71 71 71 69 65 119 -Hard 2 50 4 77 71 71 71 71 71 71 71 69 65 119 -Hard 2 50 10 77 71 71 71 71 71 71 70 69 65 119 -Hard 2 100 2 70 65 65 65 65 65 65 64 62 53 118 -Hard 2 100 4 70 65 65 65 65 65 65 64 62 53 118 -Hard 2 100 10 70 65 65 65 65 65 65 64 62 53 118 -Hard 2 200 2 64 60 60 60 60 60 59 58 54 37 118 -Hard 2 200 4 63 59 59 59 59 59 59 57 53 36 117 -Hard 2 200 10 63 59 59 59 59 59 58 57 52 36 117 -Hard 2 500 2 56 53 53 53 53 52 52 49 37 -5 117 -Hard 2 500 4 55 53 53 53 52 52 51 48 37 -6 117 -Hard 2 500 10 54 52 52 52 51 51 50 47 36 -7 116 -Soft 2 50 2 73 71 71 67 60 65 68 68 66 62 115 121Soft 2 50 4 74 71 71 66 63 67 68 68 66 62 116 120Soft 2 50 10 74 71 71 67 64 66 68 67 66 62 116 120Soft 2 100 2 67 65 65 60 52 58 61 61 59 50 114 121Soft 2 100 4 67 65 65 59 55 60 62 61 59 50 115 120Soft 2 100 10 67 65 65 61 57 60 62 61 59 50 115 120Soft 2 200 2 59 60 60 53 44 51 55 54 49 33 113 122Soft 2 200 4 60 59 59 52 48 53 55 54 49 33 114 119Soft 2 200 10 60 59 59 54 50 53 55 54 49 33 114 119Soft 2 500 2 49 53 53 42 36 43 46 43 32 -10 111 121Soft 2 500 4 49 53 53 42 40 45 46 43 32 -10 111 119Soft 2 500 10 49 52 52 45 42 45 46 43 32 -10 111 117

TABLE A7.1: Results of Noise Model for Point Source cont/…

GroundSource

Height, mSource - Rec

Dist, mReceiver Height, m

Overall dB(A)

Octave Band Centre Frequency, Hz Resultant Lw, dB(A)

AT 5414/2 Rev 1


ground effects

FLAT SOUND POWER LEVEL SPECTRUM 120 113 113 113 113 113 113 113 113 113

GroundSource



Overall dB(A)


Sound Pressure Level:Hard 5 50 2 77 71 71 71 71 71 71 71 69 65 119 -Hard 5 50 4 77 71 71 71 71 71 71 71 69 65 119 -Hard 5 50 10 77 71 71 71 71 71 71 71 69 65 119 -Hard 5 100 2 70 65 65 65 65 65 65 64 62 53 118 -Hard 5 100 4 70 65 65 65 65 65 65 64 62 53 118 -Hard 5 100 10 70 65 65 65 65 65 65 64 62 53 118 -Hard 5 200 2 63 59 59 59 59 59 58 57 52 36 117 -Hard 5 200 4 63 59 59 59 59 59 58 57 52 36 117 -Hard 5 200 10 63 59 59 59 59 59 58 57 52 36 117 -Hard 5 500 2 55 53 53 53 52 52 51 48 36 -6 117 -Hard 5 500 4 55 52 52 52 52 51 51 48 36 -6 117 -Hard 5 500 10 54 51 51 51 51 50 50 47 35 -7 115 -Soft 5 50 2 74 71 71 65 64 67 68 68 66 62 116 120Soft 5 50 4 74 71 71 64 66 68 68 68 66 62 116 119Soft 5 50 10 74 71 71 66 67 68 68 68 66 62 116 119Soft 5 100 2 67 65 65 58 56 60 62 61 59 50 115 120Soft 5 100 4 67 65 65 57 59 62 62 61 59 50 115 118Soft 5 100 10 67 65 65 59 61 62 62 61 59 50 115 118Soft 5 200 2 60 59 59 52 49 53 55 54 49 33 114 119Soft 5 200 4 60 59 59 50 53 56 55 54 49 33 114 117Soft 5 200 10 60 59 59 53 55 56 55 54 49 33 114 117Soft 5 500 2 49 53 53 42 41 45 46 43 32 -10 111 118Soft 5 500 4 50 52 52 41 45 47 46 43 32 -10 112 116Soft 5 500 10 50 51 51 44 47 47 46 43 32 -10 112 115


AT 5414/2 Rev 1


ground effects


GroundSource



Overall dB(A)




AT 5414/2 Rev 1


ground effects


GroundSource



Overall dB(A)



TABLE A7.1: Results of Noise Model for Point Source

AT 5414/2 Rev 1


ground effects

MEAN INDUSTRY SOUND POWER LEVEL SP 120 137 132 124 119 117 115 111 108 104Sound Pressure Level:



GroundSource



Overall dB(A)


AT 5414/2 Rev 1


ground effects

MEAN INDUSTRY SOUND POWER LEVEL SP 120 137 132 124 119 117 115 111 108 104

GroundSource



Overall dB(A)




AT 5414/2 Rev 1


ground effects


GroundSource



Overall dB(A)




AT 5414/2 Rev 1


ground effects

HUMPED SOUND POWER LEVEL SPECTRUM 120 106 109 112 115 118 115 112 109 106Sound Pressure Level:



Receiver Height, m

Overall dB(A)


GroundSource


Dist, m

AT 5414/2 Rev 1


ground effects

HUMPED SOUND POWER LEVEL SPECTRUM 120 106 109 112 115 118 115 112 109 106

Receiver Height, m

Overall dB(A)


GroundSource


Dist, m



AT 5414/2 Rev 1


ground effects


Receiver Height, m

Overall dB(A)


GroundSource


Dist, m



AT 5414/2 Rev 1

31.5 63 125 250 500 1k 2k 4k 8kNo

correctionCorrected for 500Hz

ground effects

SLOPED DOWN SOUND POWER LEVEL SPEC 120 129 126 123 120 117 114 111 108 105Sound Pressure Level:



Receiver Height, m

Overall dB(A)


GroundSource


Dist, m

AT 5414/2 Rev 1

31.5 63 125 250 500 1k 2k 4k 8kNo


ground effects

SLOPED DOWN SOUND POWER LEVEL SPEC 120 129 126 123 120 117 114 111 108 105

Receiver Height, m

Overall dB(A)


GroundSource


Dist, m



AT 5414/2 Rev 1

31.5 63 125 250 500 1k 2k 4k 8kNo


ground effects


Receiver Height, m

Overall dB(A)


GroundSource


Dist, m



AT 5414/2 Rev 1

31.5 63 125 250 500 1k 2k 4k 8kNo


ground effects

SLOPED UP SOUND POWER LEVEL SPECTR 120 93 96 99 102 105 108 111 114 117Sound Pressure Level:



GroundSource



Overall dB(A)


AT 5414/2 Rev 1

31.5 63 125 250 500 1k 2k 4k 8kNo


ground effects

SLOPED UP SOUND POWER LEVEL SPECTR 120 93 96 99 102 105 108 111 114 117

GroundSource



Overall dB(A)




AT 5414/2 Rev 1

31.5 63 125 250 500 1k 2k 4k 8kNo


ground effects


GroundSource



Overall dB(A)




AT 5414/2 Rev 1


KEY: How to View the Calculation Summary Sheets Model Measurement at 1.5 m height and 50,100,150 m Contours at 50 m, 100 m, 250 m, 500 m, 1000 m, 2000 m Dimensions (m) : 150 x 80 x 10

Error LpA Calc - LpA True at distances from centre, m, (assume 50% "soft" ground),

receiver height 4m

Measure - source

distance, m (to side of building)

Back calc Lw using

500 Hz

Measure-ment points 100 250 500 1000 2000

50 500 1 short 7.9 -2.1 -2 -1.2 -0.9 50 500 1 long 2.7 -7.4 -7.3 -6.5 -6.2 50 500 Average 6.0 -3.9 -3.9 -3.1 -2.8 50 Full 1 short 1.9 -8.4 -8.4 -7.5 -6.6 50 Full 1 long 2.7 -7.6 -7.6 -6.7 -5.9 50 Full Average 2.3 -7.9 -7.9 -7.1 -6.2 100 500 1 short 5.8 -4.2 -4.1 -3.3 -3 100 500 1 long 6.2 -3.8 -3.7 -2.9 -2.6 100 500 Average 6 -4 -3.9 -3.1 -2.8 100 Full 1 short 5.7 -4.7 -4.8 -4.1 -3.5 100 Full 1 long 6.2 -4.2 -4.3 -3.7 -3.1 100 Full Average 5.9 -4.4 -4.5 -3.9 -3.3 150 500 1 short 7.4 -2.6 -2.5 -1.7 -1.4 150 500 1 long 7.4 -2.6 -2.5 -1.7 -1.4 150 500 Average 7.4 -2.6 -2.5 -1.7 -1.4 150 Full 1 short 7.7 -2.8 -3.1 -2.5 -2.2 150 Full 1 long 7.7 -2.8 -3.1 -2.5 -2.2 150 Full Average 7.7 -2.8 -3.1 -2.5 -2.2

Calculation configuration:

10 m high buildings Model using a falling spectrum


Back-calculation done for hard ground (G = 0),

without barrier effect, for 500Hz and full spectrum


Contours are calculated with CADNA for mixed

ground (G = 0.5)

-100

-100

-50

-50

0

0

50

50

100

100

150

150

200

200

250

250

300

300

350

350

400

400

800

800

850

850

900

900

950

950

1000

1000

1050

1050

1100

1100

> -99.0 dB > 22.0 dB > 24.0 dB > 25.0 dB > 25.5 dB > 26.0 dB > 26.5 dB > 27.0 dB > 27.5 dB > 28.0 dB > 29.0 dB > 30.0 dB -100

-100

-50

-50

0

0

50

50

100

100

150

150

200

200

250

250

300

300

350

350

400

400

750

750

800

800

850

850

900

900

950

950

1000

1000

1050

1050

1100

1100

> -99.0 dB > 22.0 dB > 24.0 dB > 25.0 dB > 25.5 dB > 26.0 dB > 26.5 dB > 27.0 dB > 27.5 dB > 28.0 dB > 29.0 dB > 30.0 dB

Long

Short

G=0.5

G=0.5

G=0 at 50,100,150m (4m and 1.5m)

Lw true

Lp meas (true)

Lp contours (true)


XL

GENERAL SUMMARY OF THE MODEL SET UP AND GRAPHICAL

REPRESENTATION OF MODELLING CONCEPT

GRAPHICAL DEPICTION OF THE CALCULATION PROCEDURE

TABULATED VALUES FOR THE CALCULATED ERRORS

SUMMARY OF CALCULATION SET UP AND CALCULATION

METHODS AND PARAMETERS USED

CONTOUR PLOT OF THE “REAL” SITUATION

CONTOUR PLOT OF THE “ASSUMED” SITUATION


SUMMARY SHEET A7.1: Point Source Modelled as a Point Source Model + Point Source + Point Source Point Source at 2 m height “Measurements” at 1.5 m height Contours at 50 m, 100 m, 250 m, 500 m, 1000 m, 2000 m For back calculation, the distance between the source and the measurements has been set at 100 m.

Summary of Results

Error LpA true - LpA calc at distances from centre,

(assume 50% "soft" ground), receiver height 4m Spectrum

type

True ground cover

Back calc Lw using full

octave or 500 Hz 50 100 250 500 1000 2000

Fall Hard 500 0.1 0.1 0.6 0.7 1.1 2.0 Fall Hard Full 0.2 0.2 0.2 0.2 0.2 0.2 Fall Soft 500 4.4 4.4 4.9 5.0 5.4 6.3 Fall Soft Full 4.0 4.0 4.0 4.1 4.2 4.3

Hump Hard 500 0.4 0.5 0.9 0.9 1.1 1.4 Hump Hard Full -0.1 0.0 -0.1 0.0 0.0 0.0 Hump Soft 500 4.2 4.3 4.7 4.7 4.9 5.2 Hump Soft Full 3.6 3.6 3.6 3.8 4.0 4.3 Rising Hard 500 1.9 0.9 -0.4 -2.0 -3.3 -4.7 Rising Hard Full 0.2 0.2 0.2 0.2 0.2 0.2 Rising Soft 500 5.0 4.0 2.7 1.1 -0.2 -1.6 Rising Soft Full 3.2 3.3 3.3 3.4 3.5 3.7

Industrial Hard 500 0.3 0.3 1.0 1.1 1.8 3.0 Industrial Hard Full -0.1 -0.2 -0.1 -0.2 -0.1 -0.1 Industrial Soft 500 4.2 4.2 4.9 5.0 5.7 6.9 Industrial Soft Full 3.3 3.2 3.2 3.0 2.9 2.5

Calculation configuration

Models using different types of spectrum Back-calculation done with XL for hard

ground (G = 0) “Assumed Ground Cover” for a single frequency (500 Hz) and full spectrum


Contours calculated with CADNA for mixed

ground (G = 0.5) “True Ground Cover”

-60

-60

-40

-40

-20

-20

0

0

20

20

40

40

60

60

80

80

100

100

120

120

140

140

160

160

180

180

200

200

220

220

240

240

260

260

280

280

820

820

840

840

860

860

880

880

900

900

920

920

940

940

960

960

980

980

1000

1000

1020

1020

1040

1040

1060

1060


-60

-40

-40

-20

-20

0

0

20

20

40

40

60

60

80

80

100

100

120

120

140

140

160

160

180

180

200

200

220

220

240

240

260

260

280

280

820

820

840

840

860

860

880

880

900

900

920

920

940

940

960

960

980

980

1000

1000

1020

1020

1040

1040

1060

1060


True model Point Source (reality) Assume Point Source (calculated)


Lw true

Lp meas (true)

Lp contours (true)


G=0.5

G=0.5

XL


SUMMARY SHEET A7.2: Point Source Modelled as a Point Source

Model + Point Source + Point Source Point Source at 2 m height Measurements at 1.5 m height Contours at 50 m, 100 m, 250 m, 500 m, 1000 m, 2000 m For back calculation, the distance between the source and the measurements has been set at 50 m.

Summary of Results

Error LpA true - LpA calc at distances from centre, (assume

50% "soft" ground), receiver height 4m Spectrum

type

True ground cover

Back calc Lw using

full octave or 500 Hz 50 100 250 500 1000 2000

Fall Hard 500 -0.4 -0.5 -0.1 0.0 0.3 1.1 Fall Hard Full 0.2 0.2 0.2 0.2 0.2 0.2 Fall Soft 500 3.6 3.5 3.9 4.0 4.3 5.1 Fall Soft Full 3.7 3.7 3.7 3.8 3.8 3.8

Hump Hard 500 -0.2 -0.2 0.1 0.1 0.2 0.4 Hump Hard Full -0.1 0.0 -0.1 0.0 0.0 0.0 Hump Soft 500 3.4 3.4 3.7 3.7 3.8 4.0 Hump Soft Full 3.3 3.4 3.4 3.5 3.6 3.8 Rising Hard 500 0.1 -1.0 -2.4 -4.0 -5.4 -6.9 Rising Hard Full 0.2 0.2 0.2 0.2 0.2 0.2 Rising Soft 500 3.2 2.1 0.7 -0.9 -2.3 -3.8 Rising Soft Full 3.2 3.3 3.3 3.3 3.4 3.5

Industrial Hard 500 -0.2 -0.3 0.3 0.4 1.0 2.1 Industrial Hard Full -0.1 -0.2 -0.1 -0.2 -0.1 -0.1 Industrial Soft 500 3.5 3.4 4.0 4.1 4.7 5.8 Industrial Soft Full 3.2 3.1 3.1 2.9 2.8 2.5


Models using different types of spectrum Back-calculation done with XL for hard ground

(G = 0) “Assumed Ground Cover” for a single frequency (500 Hz) and full spectrum



ground (G=0.5) “True Ground Cover”

-60

-60

-40

-40

-20

-20

0

0

20

20

40

40

60

60

80

80

100

100

120

120

140

140

160

160

180

180

200

200

220

220

240

240

260

260

280

280

820

820

840

840

860

860

880

880

900

900

920

920

940

940

960

960

980

980

1000

1000

1020

1020

1040

1040

1060

1060


-60

-40

-40

-20

-20

0

0

20

20

40

40

60

60

80

80

100

100

120

120

140

140

160

160

180

180

200

200

220

220

240

240

260

260

280

280

820

820

840

840

860

860

880

880

900

900

920

920

940

940

960

960

980

980

1000

1000

1020

1020

1040

1040

1060

1060




Lw true

Lp meas (true)

Lp contours (true)


G=0.5

G=0.5

XL


SUMMARY SHEET A7.3: Point Source Modelled as a Point Source Model + Point Source + Point Source Point Source at 2 m height Measurements at 4 m height Contours at 50 m, 100 m, 250 m, 500 m, 1000 m, 2000 m For back calculation, the distance between the source and the measurements has been set at 100 m.

Summary of Results

Error LpA true - LpA calc at distances from centre, m,


type

True ground cover

Back calc Lw using

full octave or 500 Hz 50 100 250 500 1000 2000

Fall Hard 500 0.3 0.2 -0.3 -0.7 -1.3 -1.6 Fall Hard Full 0.2 0.2 0.2 0.2 0.2 0.2 Fall Soft 500 5.4 5.4 5.9 6.0 6.4 7.3 Fall Soft Full 4.6 4.6 4.6 4.9 5.1 5.3

Hump Hard 500 0.4 0.5 0.9 0.9 1.1 1.4 Hump Hard Full -0.1 0.0 -0.1 0.0 0.0 0.0 Hump Soft 500 5.3 5.4 5.8 5.8 6.0 6.3 Hump Soft Full 4.6 4.8 4.9 5.3 5.8 6.5 Rising Hard 500 1.9 0.9 -0.4 -2.0 -3.3 -4.7 Rising Hard Full 0.2 0.2 0.2 0.2 0.2 0.2 Rising Soft 500 5.1 4.1 2.8 1.2 -0.1 -1.5 Rising Soft Full 3.3 3.5 3.6 3.9 4.3 5.0

Industrial Hard 500 0.3 0.3 1.0 1.1 1.8 3.0 Industrial Hard Full -0.1 -0.2 -0.1 -0.2 -0.1 -0.1 Industrial Soft 500 5.0 5.0 5.7 5.8 6.5 7.7 Industrial Soft Full 4.1 4.1 4.1 3.9 3.8 3.3







-60

-60

-40

-40

-20

-20

0

0

20

20

40

40

60

60

80

80

100

100

120

120

140

140

160

160

180

180

200

200

220

220

240

240

260

260

280

280

820

820

840

840

860

860

880

880

900

900

920

920

940

940

960

960

980

980

1000

1000

1020

1020

1040

1040

1060

1060


-60

-40

-40

-20

-20

0

0

20

20

40

40

60

60

80

80

100

100

120

120

140

140

160

160

180

180

200

200

220

220

240

240

260

260

280

280

820

840

860

880

900

920

940

960

980

1000

1020

1040

1060

> -99.0 d > 35.0 d > 40.0 d > 45.0 d > 50.0 d > 55.0 d > 60.0 d > 65.0 d > 70.0 d > 75.0 d > 80.0 d > 85.0 d



Lw true

Lp meas (true)

Lp contours (true)


G=0.5

G=0.5

XL


SUMMARY SHEET A7.4: Point Source Modelled as a Point Source Model + Point Source + Point Source Point Source at 2 m height Measurements at 4 m height Contours at 50 m, 100 m, 250 m, 500 m, 1000 m, 2000 m For back calculation, the distance between the source and the measurements has been set at 50 m.

Summary of Results



type

True ground cover

Back calc Lw using

full octave or 500 Hz 50 100 250 500 1000 2000

Fall Hard 500 0.1 0.0 -0.5 -0.9 -1.5 -1.8 Fall Hard Full 0.2 0.2 0.2 0.2 0.2 0.2 Fall Soft 500 4.4 4.3 4.7 4.8 5.1 5.9 Fall Soft Full 4.3 4.3 4.3 4.5 4.7 4.8

Hump Hard 500 -0.2 -0.2 0.1 0.1 0.2 0.4 Hump Hard Full -0.1 0.0 -0.1 0.0 0.0 0.0 Hump Soft 500 4.3 4.3 4.6 4.6 4.7 4.9 Hump Soft Full 4.5 4.6 4.7 5.1 5.5 6.1 Rising Hard 500 0.1 -1.0 -2.4 -4.0 -5.4 -6.9 Rising Hard Full 0.2 0.2 0.2 0.2 0.2 0.2 Rising Soft 500 3.3 2.2 0.8 -0.8 -2.2 -3.7 Rising Soft Full 3.2 3.3 3.4 3.4 3.7 4.0

Industrial Hard 500 -0.2 -0.3 0.3 0.4 1.0 2.1 Industrial Hard Full -0.1 -0.2 -0.1 -0.2 -0.1 -0.1 Industrial Soft 500 4.2 4.1 4.7 4.8 5.4 6.5 Industrial Soft Full 4.0 3.9 3.9 3.7 3.6 3.1







-60

-60

-40

-40

-20

-20

0

0

20

20

40

40

60

60

80

80

100

100

120

120

140

140

160

160

180

180

200

200

220

220

240

240

260

260

280

280

820

820

840

840

860

860

880

880

900

900

920

920

940

940

960

960

980

980

1000

1000

1020

1020

1040

1040

1060

1060


-60

-40

-40

-20

-20

0

0

20

20

40

40

60

60

80

80

100

100

120

120

140

140

160

160

180

180

200

200

220

220

240

240

260

260

280

280

820

820

840

840

860

860

880

880

900

900

920

920

940

940

960

960

980

980

1000

1000

1020

1020

1040

1040

1060

1060




Lw true

Lp meas (true)

Lp contours (true)


G=0.5

G=0.5

XL


SUMMARY SHEET A7.5: Point Source Modelled as a Point Source Model + Point Source + Point Source Point Source at 4 m height Measurements at 1.5 m height Contours at 50 m, 100 m, 250 m, 500 m, 1000 m, 2000 m For back calculation, the distance between the source and measurements has been set at 100 m.

Summary of Results



type

True ground cover

Back calc Lw using

full octave or 500 Hz 50 100 250 500 1000 2000

Fall Hard 500 -0.1 -0.4 -0.8 -1.2 -1.6 -1.8 Fall Hard Full 0.2 0.2 0.2 0.2 0.2 0.2 Fall Soft 500 4.9 4.6 4.2 3.8 3.4 3.2 Fall Soft Full 4.6 4.6 4.8 4.9 5.2 5.4

Hump Hard 500 0.2 -0.1 -0.5 -1.1 -1.7 -2.4 Hump Hard Full 0.0 -0.1 0.0 -0.1 0.0 0.0 Hump Soft 500 4.7 4.4 4.0 3.4 2.8 2.1 Hump Soft Full 4.5 4.6 4.9 5.0 5.5 6.0 Rising Hard 500 1.5 0.0 -2.3 -4.3 -6.6 -8.9 Rising Hard Full 0.2 0.2 0.2 0.2 0.2 0.2 Rising Soft 500 4.7 3.2 0.9 -1.1 -3.4 -5.7 Rising Soft Full 3.3 3.3 3.4 3.6 3.7 4.3

Industrial Hard 500 0.0 -0.2 -0.6 -0.8 -1.1 -1.0 Industrial Hard Full -0.2 -0.1 -0.2 -0.1 -0.1 -0.1 Industrial Soft 500 4.5 4.3 3.9 3.7 3.4 3.5 Industrial Soft Full 4.1 4.2 4.2 4.2 4.1 3.6







-60

-60

-40

-40

-20

-20

0

0

20

20

40

40

60

60

80

80

100

100

120

120

140

140

160

160

180

180

200

200

220

220

240

240

260

260

280

280

820

820

840

840

860

860

880

880

900

900

920

920

940

940

960

960

980

980

1000

1000

1020

1020

1040

1040

1060

1060


-60

-40

-40

-20

-20

0

0

20

20

40

40

60

60

80

80

100

100

120

120

140

140

160

160

180

180

200

200

220

220

240

240

260

260

280

280

820

840

860

880

900

920

940

960

980

1000

1020

1040

1060




Lw true

Lp meas (true)

Lp contours (true)


G=0.5

G=0.5

XL


SUMMARY SHEET A7.6: Point Source Modelled as a Point Source Model + Point Source + Point Source Point Source at 4 m height Measurements at 1.5 m height Contours at 50 m, 100 m, 250 m, 500 m, 1000 m, 2000 m For back calculation, the distance between the source and measurements has been set at 50 m.

Summary of Results Error LpA true - LpA calc at distances from centre, m,


type

True ground cover

Back calc Lw using

full octave or 500 Hz 50 100 250 500 1000 2000


Hump Hard 500 -0.1 -0.4 -0.8 -1.4 -2.0 -2.7 Hump Hard Full 0.0 -0.1 0.0 -0.1 0.0 0.0 Hump Soft 500 4.1 3.8 3.4 2.8 2.2 1.5 Hump Soft Full 3.9 3.9 4.1 4.2 4.6 5.0 Rising Hard 500 0.0 -1.5 -3.8 -5.8 -8.1 -10.4Rising Hard Full 0.2 0.2 0.2 0.2 0.2 0.2 Rising Soft 500 3.1 1.6 -0.7 -2.7 -5.0 -7.3 Rising Soft Full 3.3 3.3 3.3 3.5 3.6 4.1

Industrial Hard 500 -0.2 -0.4 -0.8 -1.0 -1.3 -1.2 Industrial Hard Full -0.2 -0.1 -0.2 -0.1 -0.1 -0.1 Industrial Soft 500 3.9 3.7 3.3 3.1 2.8 2.9 Industrial Soft Full 3.9 4.0 4.0 4.0 3.8 3.3







-60

-60

-40

-40

-20

-20

0

0

20

20

40

40

60

60

80

80

100

100

120

120

140

140

160

160

180

180

200

200

220

220

240

240

260

260

280

280

820

820

840

840

860

860

880

880

900

900

920

920

940

940

960

960

980

980

1000

1000

1020

1020

1040

1040

1060

1060


-60

-40

-40

-20

-20

0

0

20

20

40

40

60

60

80

80

100

100

120

120

140

140

160

160

180

180

200

200

220

220

240

240

260

260

280

280

820

820

840

840

860

860

880

880

900

900

920

920

940

940

960

960

980

980

1000

1000

1020

1020

1040

1040

1060

1060




Lw true

Lp meas (true)

Lp contours (true)


G=0.5

G=0.5

XL


SUMMARY SHEET A7.7: Point Source Modelled as a Point Source Model + Point Source + Point Source Point Source at 4 m height Measurements at 4 m height Contours at 50 m, 100 m, 250 m, 500 m, 1000 m, 2000 m For back calculation, the distance between source and measure has been set at 100 m.

Summary of Results


(assume 50% "soft" ground), receiver height 4 m Spectrum

type

True ground cover

Back calc Lw using

full octave or 500 Hz 50 100 250 500 1000 2000


Hump Hard 500 0.2 -0.1 -0.5 -1.1 -1.7 -2.4 Hump Hard Full 0.0 -0.1 0.0 -0.1 0.0 0.0 Hump Soft 500 3.3 3.0 2.6 2.0 1.4 0.7 Hump Soft Full 3.1 3.0 3.1 3.1 3.2 3.2 Rising Hard 500 1.5 0.0 -2.3 -4.3 -6.6 -8.9 Rising Hard Full 0.2 0.2 0.2 0.2 0.2 0.2 Rising Soft 500 4.5 3.0 0.7 -1.3 -3.6 -5.9 Rising Soft Full 3.2 3.2 3.2 3.3 3.2 3.3

Industrial Hard 500 0.0 -0.2 -0.6 -0.8 -1.1 -1.0 Industrial Hard Full -0.2 -0.1 -0.2 -0.1 -0.1 -0.1 Industrial Soft 500 3.3 3.1 2.7 2.5 2.2 2.3 Industrial Soft Full 2.8 2.8 2.8 2.7 2.6 2.3







-60

-60

-40

-40

-20

-20

0

0

20

20

40

40

60

60

80

80

100

100

120

120

140

140

160

160

180

180

200

200

220

220

240

240

260

260

280

280

820

820

840

840

860

860

880

880

900

900

920

920

940

940

960

960

980

980

1000

1000

1020

1020

1040

1040

1060

1060


-60

-40

-40

-20

-20

0

0

20

20

40

40

60

60

80

80

100

100

120

120

140

140

160

160

180

180

200

200

220

220

240

240

260

260

280

280

820

820

840

840

860

860

880

880

900

900

920

920

940

940

960

960

980

980

1000

1000

1020

1020

1040

1040

1060

1060




Lw true

Lp meas (true)

Lp contours (true)


G=0.5

G=0.5

XL


SUMMARY SHEET A7.8: Point Source Modelled as a Point Source Model + Point Source + Point Source Point Source at 4 m height Measurements at 4 m height Contours at 50 m, 100 m, 250 m, 500 m, 1000 m, 2000 m For back calculation, the distance between source and measure has been set at 50 m.

Summary of Results



type

True ground cover

Back calc Lw using

full octave or 500 Hz 50 100 250 500 1000 2000


Hump Hard 500 -0.1 -0.4 -0.8 -1.4 -2.0 -2.7 Hump Hard Full 0.0 -0.1 0.0 -0.1 0.0 0.0 Hump Soft 500 3.0 2.7 2.3 1.7 1.1 0.4 Hump Soft Full 3.0 3.0 3.1 3.0 3.1 3.2 Rising Hard 500 0.0 -1.5 -3.8 -5.8 -8.1 -10.4Rising Hard Full 0.2 0.2 0.2 0.2 0.2 0.2 Rising Soft 500 3.0 1.5 -0.8 -2.8 -5.1 -7.4 Rising Soft Full 3.2 3.2 3.2 3.2 3.2 3.3

Industrial Hard 500 -0.2 -0.4 -0.8 -1.0 -1.3 -1.2 Industrial Hard Full -0.2 -0.1 -0.2 -0.1 -0.1 -0.1 Industrial Soft 500 3.0 2.8 2.4 2.2 1.9 2.0 Industrial Soft Full 2.7 2.8 2.7 2.6 2.5 2.2







-60

-60

-40

-40

-20

-20

0

0

20

20

40

40

60

60

80

80

100

100

120

120

140

140

160

160

180

180

200

200

220

220

240

240

260

260

280

280

820

820

840

840

860

860

880

880

900

900

920

920

940

940

960

960

980

980

1000

1000

1020

1020

1040

1040

1060

1060


-60

-40

-40

-20

-20

0

0

20

20

40

40

60

60

80

80

100

100

120

120

140

140

160

160

180

180

200

200

220

220

240

240

260

260

280

280

820

820

840

840

860

860

880

880

900

900

920

920

940

940

960

960

980

980

1000

1000

1020

1020

1040

1040

1060

1060




Lw true

Lp meas (true)

Lp contours (true)


G=0.5

G=0.5

XL

APPENDIX 8:

Noise Modelling Summary Sheets – Building With Even Radiation


AT5414/2 Rev 1 Acoustic Technology

SUMMARY SHEET A8.1: Building Modelled by a Building Model Measurements at 4 m height and at 50 m, 100 m, 150 m Contours at 50 m, 100 m, 250 m, 500 m, 1000 m, 2000 m Dimensions (m) : 150*80*10

Error LpA true - LpA calc at distances from centre, m, (assume 50% "soft" ground),

receiver height 4m

Measure - source

distance (to side of building)

Back calc Lw using

full octave or 500 Hz?

Measure-ment points

100 250 500 1000 2000

50 500 1 short -1.0 -1.6 -1.7 -2.3 -2.3 50 500 1 long 0.8 0.2 0.1 -0.5 -0.5 50 500 Average -0.2 -0.8 -0.9 -1.5 -1.5 50 Full 1 short -1.1 -0.8 -0.4 -0.6 -0.5 50 Full 1 long 0.3 0.4 0.7 0.5 0.5 50 Full Average -0.5 -0.2 0.1 -0.1 0.0

100 500 1 short 0.3 -0.3 -0.4 -1.0 -1.0 100 500 1 long 1.0 0.4 0.3 -0.3 -0.3 100 500 Average 0.6 0.0 -0.1 -0.7 -0.7 100 Full 1 short 0.2 0.3 0.7 0.5 0.5 100 Full 1 long 0.3 0.4 0.7 0.5 0.5 100 Full Average 0.2 0.3 0.7 0.5 0.5 150 500 1 short 0.9 0.3 0.2 -0.4 -0.4 150 500 1 long 1.2 0.6 0.5 -0.1 -0.1 150 500 Average 1.0 0.4 0.3 -0.3 -0.3 150 Full 1 short 0.2 0.3 0.7 0.5 0.5 150 Full 1 long 0.6 0.7 1.0 0.7 0.8 150 Full Average 0.4 0.5 0.8 0.6 0.6


10 m high building Assume 10 m high building


Lw’’ = 90 dB/m² for each Façade


without barrier effect, for 500 Hz and full spectrum



ground (G = 0.5) without barrier effect

-140

-140

-120

-120

-100

-100

-80

-80

-60

-60

-40

-40

-20

-20

0

0

20

20

40

40

60

60

80

80

100

100

120

120

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140

160

160

180

180

200

200

220

220

240

240

260

260

280

280

300

300

320

320

340

340

360

360

720

720

740

740

760

760

780

780

800

800

820

820

840

840

860

860

880

880

900

900

920

920

940

940

960

960

980

980

1000

1000

1020

1020

1040

1040


-140

-120

-120

-100

-100

-80

-80

-60

-60

-40

-40

-20

-20

0

0

20

20

40

40

60

60

80

80

100

100

120

120

140

140

160

160

180

180

200

200

220

220

240

240

260

260

280

280

300

300

320

320

340

340

360

360

720

720

740

740

760

760

780

780

800

800

820

820

840

840

860

860

880

880

900

900

920

920

940

940

960

960

980

980

1000

1000

1020

1020

1040

1040


Building Sources on each façade (reality) Assume Building (calculated)

G=0.5

G=0 at 50,100,150m

G=0.5 Lw true

Lp meas (true)

Lp contours (true)


XL

Short

Long

Short

Long


SUMMARY SHEET A8.2: Building Modelled by One Point Source Model Measurements at 4 m height and at 50 m, 100 m, 150 m Contours at 50 m, 100 m, 250 m, 500 m, 1000 m, 2000 m Dimensions (m) : 150*80*10


receiver height 4m

Measure - source


Back calc Lw using

full octave or 500 Hz

Measure-ment points

100 250 500 1000 2000

50 500 1 short 1.5 -2.2 -3.0 -3.6 -3.5 50 500 1 long 3.5 -0.2 -1.0 -1.6 -1.5 50 500 Average 2.4 -1.3 -2.1 -2.7 -2.6 50 Full 1 short 1.3 -1.8 -2.3 -2.5 -2.2 50 Full 1 long 3.4 0.2 -0.3 -0.5 -0.2 50 Full Average 2.2 -0.9 -1.4 -1.6 -1.3

100 500 1 short 2.8 -0.9 -1.7 -2.3 -2.2 100 500 1 long 3.5 -0.2 -1.0 -1.6 -1.5 100 500 Average 3.1 -0.6 -1.4 -2.0 -1.9 100 Full 1 short 2.4 -0.8 -1.3 -1.4 -1.2 100 Full 1 long 3.4 0.2 -0.3 -0.5 -0.2 100 Full Average 2.9 -0.3 -0.8 -1.0 -0.7 150 500 1 short 3.3 -0.4 -1.2 -1.8 -1.7 150 500 1 long 3.6 -0.1 -0.9 -1.5 -1.4 150 500 Average 3.5 -0.2 -1.0 -1.6 -1.5 150 Full 1 short 3.3 0.2 -0.3 -0.5 -0.2 150 Full 1 long 3.4 0.2 -0.3 -0.5 -0.2 150 Full Average 3.3 0.2 -0.3 -0.5 -0.2


10 m high building Assume Point Source at 5 m height








-140

-140

-120

-120

-100

-100

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-80

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-60

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-20

0

0

20

20

40

40

60

60

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120

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160

180

180

200

200

220

220

240

240

260

260

280

280

300

300

320

320

340

340

360

360

720

720

740

740

760

760

780

780

800

800

820

820

840

840

860

860

880

880

900

900

920

920

940

940

960

960

980

980

1000

1000

1020

1020

1040

1040


-140

-120

-120

-100

-100

-80

-80

-60

-60

-40

-40

-20

-20

0

0

20

20

40

40

60

60

80

80

100

100

120

120

140

140

160

160

180

180

200

200

220

220

240

240

260

260

280

280

300

300

320

320

340

340

360

360

380

380

720

720

740

740

760

760

780

780

800

800

820

820

840

840

860

860

880

880

900

900

920

920

940

940

960

960

980

980

1000

1000

1020

1020

1040

1040


Building Sources on each façade (reality) Assume Point Source (calculated)

G=0.5

G=0 at 50,100,150m

G=0.5 Lw true

Lp meas (true)

Lp contours (true)


XL

Short

Long




(assume 50% "soft" ground), receiver

height 4m

Measure - source distance

(to side of building)

Back calc Lw using


Measure-ment points

100 250 500 1000 200050 500 1 short 1.5 -2.1 -2.8 -3.2 -3.3 50 500 1 long 3.1 -0.5 -1.2 -1.6 -1.7 50 500 Average 2.2 -1.4 -2.1 -2.5 -2.6 50 Full 1 short 1.8 -1.3 -1.6 -1.5 -1.3 50 Full 1 long 3.8 0.7 0.4 0.5 0.7 50 Full Average 2.7 -0.4 -0.7 -0.6 -0.4

100 500 1 short 2.6 -1.0 -1.7 -2.1 -2.2 100 500 1 long 3.4 -0.2 -0.9 -1.3 -1.4 100 500 Average 3.0 -0.6 -1.3 -1.7 -1.8 100 Full 1 short 2.8 -0.3 -0.6 -0.5 -0.3 100 Full 1 long 3.9 0.7 0.4 0.5 0.7 100 Full Average 3.3 0.2 -0.1 0.0 0.2 150 500 1 short 3.1 -0.5 -1.2 -1.6 -1.7 150 500 1 long 3.4 -0.2 -0.9 -1.3 -1.4 150 500 Average 3.3 -0.3 -1.0 -1.4 -1.5 150 Full 1 short 2.9 -0.3 -0.6 -0.5 -0.3 150 Full 1 long 3.9 0.7 0.4 0.5 0.7 150 Full Average 3.4 0.2 -0.1 0.0 0.2


5 m high building Assume Point Source at 2.5 m height








-140

-140

-120

-120

-100

-100

-80

-80

-60

-60

-40

-40

-20

-20

0

0

20

20

40

40

60

60

80

80

100

100

120

120

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160

180

180

200

200

220

220

240

240

260

260

280

280

300

300

320

320

340

340

360

360

720

720

740

740

760

760

780

780

800

800

820

820

840

840

860

860

880

880

900

900

920

920

940

940

960

960

980

980

1000

1000

1020

1020

1040

1040


-140

-120

-120

-100

-100

-80

-80

-60

-60

-40

-40

-20

-20

0

0

20

20

40

40

60

60

80

80

100

100

120

120

140

140

160

160

180

180

200

200

220

220

240

240

260

260

280

280

300

300

320

320

340

340

360

360

380

380

720

720

740

740

760

760

780

780

800

800

820

820

840

840

860

860

880

880

900

900

920

920

940

940

960

960

980

980

1000

1000

1020

1020

1040

1040



G=0.5

G=0 at 50,100,150m

G=0.5 Lw true

Lp meas (true)

Lp contours (true)


XL

Short

Long




receiver height 4m

Measure - source distance

(to side of building)

Back calc Lw using


Measure-ment points

100 250 500 1000 2000

50 500 1 short 1.6 -2.2 -3.2 -4.0 -4.5 50 500 1 long 3.4 -0.4 -1.4 -2.2 -2.7 50 500 Average 2.4 -1.4 -2.4 -3.2 -3.7 50 Full 1 short 1.8 -1.3 -1.8 -1.7 -1.5 50 Full 1 long 3.2 0.0 -0.6 -0.7 -0.5 50 Full Average 2.4 -0.7 -1.2 -1.2 -1.0 100 500 1 short 2.9 -0.9 -1.9 -2.7 -3.2 100 500 1 long 3.7 -0.1 -1.1 -1.9 -2.4 100 500 Average 3.3 -0.5 -1.5 -2.3 -2.8 100 Full 1 short 2.9 -0.3 -0.8 -0.7 -0.5 100 Full 1 long 3.2 0.0 -0.6 -0.7 -0.5 100 Full Average 3.0 -0.2 -0.7 -0.7 -0.5 150 500 1 short 3.6 -0.2 -1.2 -2.0 -2.5 150 500 1 long 3.9 0.1 -0.9 -1.7 -2.2 150 500 Average 3.8 0.0 -1.0 -1.8 -2.3 150 Full 1 short 3.1 -0.1 -0.6 -0.7 -0.5 150 Full 1 long 3.2 0.0 -0.6 -0.7 -0.5 150 Full Average 3.1 -0.1 -0.6 -0.7 -0.5



Model using a Humped Spectrum







-140

-140

-120

-120

-100

-100

-80

-80

-60

-60

-40

-40

-20

-20

0

0

20

20

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980

1000

1000

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1040


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860

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900

900

920

920

940

940

960

960

980

980

1000

1000

1020

1020

1040

1040



G=0.5

G=0 at 50,100,150m

G=0.5 Lw true

Lp meas (true)

Lp contours (true)


XL

Short

Long




receiver height 4m

Measure - source


Back calc Lw using



50 500 1 short 1.7 -2.0 -2.9 -3.5 -4.2 50 500 1 long 3.4 -0.3 -1.2 -1.8 -2.5 50 500 Average 2.5 -1.2 -2.1 -2.7 -3.4 50 Full 1 short 1.5 -1.7 -2.0 -1.9 -1.8 50 Full 1 long 3.6 0.3 0.0 0.1 0.2 50 Full Average 2.4 -0.8 -1.1 -1.0 -0.9 100 500 1 short 2.9 -0.8 -1.7 -2.3 -3.0 100 500 1 long 3.7 0.0 -0.9 -1.5 -2.2 100 500 Average 3.3 -0.4 -1.3 -1.9 -2.6 100 Full 1 short 2.5 -0.7 -1.0 -0.9 -0.8 100 Full 1 long 3.6 0.3 0.0 0.1 0.2 100 Full Average 3.0 -0.2 -0.5 -0.4 -0.3 150 500 1 short 3.5 -0.2 -1.1 -1.7 -2.4 150 500 1 long 3.8 0.1 -0.8 -1.4 -2.1 150 500 Average 3.7 0.0 -0.9 -1.5 -2.2 150 Full 1 short 3.3 0.1 -0.1 0.0 0.2 150 Full 1 long 3.6 0.3 0.0 0.1 0.2 150 Full Average 3.4 0.2 -0.1 0.0 0.2



Model using a Humped Spectrum







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920

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940

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960

980

980

1000

1000

1020

1020

1040

1040



G=0.5

G=0 at 50,100,150m

G=0.5 Lw true

Lp meas (true)

Lp contours (true)


XL

Short

Long




receiver height 4 m

Measure - source


Back calc Lw using


Measure-ment points

100 250 500 1000 200050 500 1 short 1.4 -2.2 -2.9 -3.4 -3.0 50 500 1 long 3.2 -0.4 -1.1 -1.6 -1.2 50 500 Average 2.2 -1.4 -2.1 -2.6 -2.2 50 Full 1 short 1.8 -1.3 -1.8 -2.0 -1.8 50 Full 1 long 3.5 0.3 -0.2 -0.3 0.0 50 Full Average 2.6 -0.6 -1.1 -1.2 -1.0 100 500 1 short 2.8 -0.8 -1.5 -2.0 -1.6 100 500 1 long 3.5 -0.1 -0.8 -1.3 -0.9 100 500 Average 3.1 -0.5 -1.2 -1.7 -1.3 100 Full 1 short 2.8 -0.3 -0.8 -1.0 -0.8 100 Full 1 long 3.5 0.3 -0.2 -0.3 0.0 100 Full Average 3.1 0.0 -0.5 -0.7 -0.4 150 500 1 short 3.3 -0.3 -1.0 -1.5 -1.1 150 500 1 long 3.6 0.0 -0.7 -1.2 -0.8 150 500 Average 3.5 -0.1 -0.8 -1.3 -0.9 150 Full 1 short 3.0 -0.2 -0.7 -0.8 -0.6 150 Full 1 long 3.5 0.3 -0.2 -0.3 0.0 150 Full Average 3.2 0.0 -0.5 -0.6 -0.3



Model using a Industrial Spectrum







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780

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860

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880

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900

900

920

920

940

940

960

960

980

980

1000

1000

1020

1020

1040

1040



G=0.5

G=0 at 50,100,150m

G=0.5 Lw true

Lp meas (true)

Lp contours (true)


XL

Short

Long


SUMMARY SHEET A8.7: Building Modelled by One Point Source Model Measurements at 4 m height and at 50 m, 100 m , 150 m Contours at 50 m, 100 m, 250 m, 500 m, 1000 m, 2000 m Dimensions (m) : 150*80*5


receiver height 4 m

Measure - source


Back calc Lw using


Measure-ment

points

100 250 500 1000 200050 500 1 short 1.5 -2.0 -2.6 -2.8 -2.7 50 500 1 long 3.2 -0.3 -0.9 -1.1 -1.0 50 500 Average 2.3 -1.2 -1.8 -2.0 -1.9 50 Full 1 short 1.4 -1.8 -2.0 -1.9 -1.8 50 Full 1 long 3.3 0.1 -0.2 0.0 0.0 50 Full Average 2.2 -1.0 -1.2 -1.1 -1.0 100 500 1 short 2.7 -0.8 -1.4 -1.6 -1.5 100 500 1 long 3.4 -0.1 -0.7 -0.9 -0.8 100 500 Average 3.0 -0.5 -1.1 -1.3 -1.2 100 Full 1 short 2.4 -0.8 -1.0 -0.9 -0.8 100 Full 1 long 3.3 0.2 -0.1 0.0 0.1 100 Full Average 2.8 -0.3 -0.6 -0.5 -0.4 150 500 1 short 3.2 -0.3 -0.9 -1.1 -1.0 150 500 1 long 3.5 0.0 -0.6 -0.8 -0.7 150 500 Average 3.4 -0.1 -0.7 -0.9 -0.8 150 Full 1 short 3.2 0.1 -0.2 0.0 0.0 150 Full 1 long 3.3 0.2 -0.1 0.0 0.1 150 Full Average 3.2 0.1 -0.2 0.0 0.0



Model using a Industrial Spectrum







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-140

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-120

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960

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980

980

1000

1000

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1040


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-100

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720

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780

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800

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840

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900

900

920

920

940

940

960

960

980

980

1000

1000

1020

1020

1040

1040



G=0.5

G=0 at 50,100,150m

G=0.5 Lw true

Lp meas (true)

Lp contours (true)


XL

Short

Long




receiver height 4 m

Measure - source


Back calc Lw using


Measure-ment points

100 250 500 1000 200050 500 1 short 2.5 -4.1 -6.8 -9.2 -11.450 500 1 long 4.3 -2.3 -5.0 -7.4 -9.6 50 500 Average 3.3 -3.3 -6.0 -8.4 -10.650 Full 1 short 1.7 -1.8 -2.4 -2.4 -2.3 50 Full 1 long 4.6 0.4 -0.3 -0.4 -0.3 50 Full Average 2.9 -0.8 -1.5 -1.5 -1.4 100 500 1 short 4.9 -1.7 -4.4 -6.8 -9.0 100 500 1 long 5.5 -1.1 -3.8 -6.2 -8.4 100 500 Average 5.2 -1.4 -4.1 -6.5 -8.7 100 Full 1 short 4.9 -1.7 -4.4 -6.8 -9.0 100 Full 1 long 4.6 0.4 -0.3 -0.4 -0.3 100 Full Average 4.7 -0.8 -2.8 -4.7 -6.5 150 500 1 short 6.2 -0.4 -3.1 -5.5 -7.7 150 500 1 long 6.3 -0.3 -3.0 -5.4 -7.6 150 500 Average 6.3 -0.3 -3.0 -5.4 -7.6 150 Full 1 short 3.9 0.2 -0.4 -0.4 -0.3 150 Full 1 long 4.6 0.4 -0.3 -0.4 -0.3 150 Full Average 4.2 0.3 -0.4 -0.4 -0.3



Model using a Rising Spectrum







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780

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840

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900

900

920

920

940

940

960

960

980

980

1000

1000

1020

1020

1040

1040



G=0.5

G=0 at 50,100,150m

G=0.5 Lw true

Lp meas (true)

Lp contours (true)


XL

Short

Long




receiver height 4m

Measure - source


Back calc Lw using


Measure-ment

points

100 250 500 1000 200050 500 1 short 2.6 -3.9 -6.4 -8.6 -10.950 500 1 long 4.2 -2.3 -4.8 -7.0 -9.3 50 500 Average 3.3 -3.2 -5.7 -7.9 -10.250 Full 1 short 1.8 -1.7 -1.9 -1.8 -1.6 50 Full 1 long 4.2 0.3 0.1 0.2 0.4 50 Full Average 2.8 -0.8 -1.0 -0.9 -0.7 100 500 1 short 6.1 -0.4 -2.9 -5.1 -7.4 100 500 1 long 6.2 -0.3 -2.8 -5.0 -7.3 100 500 Average 6.2 -0.3 -2.8 -5.0 -7.3 100 Full 1 short 2.8 -0.7 -0.9 -0.8 -0.6 100 Full 1 long 4.7 0.5 0.2 0.2 0.4 100 Full Average 3.6 -0.1 -0.4 -0.3 -0.1 150 500 1 short 4.8 -1.7 -4.2 -6.4 -8.7 150 500 1 long 5.4 -1.1 -3.6 -5.8 -8.1 150 500 Average 5.1 -1.4 -3.9 -6.1 -8.4 150 Full 1 short 3.4 -0.5 -0.8 -0.8 -0.6 150 Full 1 long 4.7 0.5 0.2 0.2 0.4 150 Full Average 4.0 0.0 -0.3 -0.3 -0.1



Model using a Rising Spectrum







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-120

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940

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960

960

980

980

1000

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720

720

740

740

760

760

780

780

800

800

820

820

840

840

860

860

880

880

900

900

920

920

940

940

960

960

980

980

1000

1000

1020

1020

1040

1040



G=0.5

G=0 at 50,100,150m

G=0.5 Lw true

Lp meas (true)

Lp contours (true)


XL

Short

Long


G=0.5

SUMMARY SHEET A8.10: Building Modelled by 2D Area Source Model smeared sources 2D Area Source Dimensions (150m x 80m x 10m) (150m x 80m) Measurement at 4 m height at 50 m, 100 m, 150 m Contours at 50 m, 100 m, 250 m, 500 m, 1000 m, 2000 m

Summary of results


receiver height 4m

Measure -

source distance, m (to side of building)

Back calc Lw using 500 Hz

Measure

-ment points

100 250 500 1000 2000

50 500 1 short 1.3 2.7 3.6 3.9 3.8 50 500 1 long -0.5 0.9 1.8 2.1 2.0 50 500 Average 0.5 1.9 2.8 3.1 3.0 50 Full 1 short 1.5 2.2 2.7 2.6 2.3 50 Full 1 long -0.6 0.2 0.7 0.6 0.3 50 Full Average 0.6 1.3 1.8 1.7 1.4

100 500 1 short 0.0 1.4 2.3 2.6 2.5 100 500 1 long -0.7 0.7 1.6 1.9 1.8 100 500 Average -0.3 1.1 2.0 2.3 2.2 100 Full 1 short 0.5 1.2 1.7 1.6 1.3 100 Full 1 long -0.6 0.2 0.7 0.6 0.3 100 Full Average 0.0 0.7 1.2 1.1 0.8 150 500 1 short -0.6 0.8 1.7 2.0 1.9 150 500 1 long -0.9 0.5 1.4 1.7 1.6 150 500 Average -0.7 0.7 1.6 1.9 1.8 150 Full 1 short -0.9 0.5 1.4 1.7 1.6 150 Full 1 long -0.6 0.2 0.7 0.6 0.3 150 Full Average -0.7 0.4 1.1 1.2 1.0


10 m high building Assume 2D Area Source at 5 m high








-100

-100

-50

-50

0

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50

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1000

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1050

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1100

1150

1150

> -99.0 dB > 40.0 dB > 45.0 dB > 50.0 dB > 55.0 dB > 60.0 dB > 65.0 dB > 70.0 dB > 75.0 dB > 80.0 dB > 85.0 dB

-100

-100

-50

-50

0

0

50

50

100

100

150

150

200

200

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500

550

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850

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900

950

950

1000

1000

1050

1050

1100

1100

1150

1150


Building with smeared sources on each façade (reality)

G=0 at 50,100,150m

G=0.5 Lw true

Lp meas (true)

Lp contours (true)


XL

Short

Long

Assume 2D Area Source (calculated)

APPENDIX 9:

Noise Modelling Summary Sheets – Building With Directional Radiation



SUMMARY SHEET A9.1: Building Radiating From One facade Modelled by a Point Source Model one façade point source Measurement at 4 m height and at 50 m, 100 m, 150 m Contours at 50 m, 100 m, 250 m, 500 m, 1000 m, 2000 m Dimensions (m): 150 x 80 x 10

Summary of results Error LpA Calc - LpA True

at distances from centre, m, (assume 50% "soft" ground),

receiver height 4m

Measure - source



50 South 21.6 17.2 14.2 20.2 17.0 50 North -9.7 -14.1 -17.1 -11.1 -14.350 East 0.5 -3.9 -6.9 -0.9 -4.1 50 West 0.5 -3.9 -6.9 -0.9 -4.1 50 Average 15.6 11.2 8.2 14.2 11.0

100 South 20.5 16.1 13.1 19.1 15.9 100 North -8.0 -12.4 -15.4 -9.4 -12.6100 East 2.9 -1.5 -4.5 1.5 -1.7 100 West 2.9 -1.5 -4.5 1.5 -1.7 100 Average 14.6 10.2 7.2 13.2 10.0 150 South 19.9 15.5 12.5 18.5 15.3 150 North -7.1 -11.5 -14.5 -8.5 -11.7150 East 3.9 -0.5 -3.5 2.5 -0.7 150 West 3.9 -0.5 -3.5 2.5 -0.7 150 Average 14.1 9.7 6.7 12.7 9.5


10 m high building Model using an industrial spectrum

Lw’’=90 dB/m² for South Façade


without barrier effect, for 500 Hz Lw = Lp + Adiv + Aatm


ground (G = 0.5)

-100

-100

-50

-50

0

0

50

50

100

100

150

150

200

200

250

250

300

300

350

350

400

400

450

450

500

500

550

550

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900

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950

1000

1000

400

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650

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800

850

900

950

1000

1050

1100

1150

> -99.0 > 35.0 > 40.0 > 45.0 > 50.0 > 55.0 > 60.0 > 65.0 > 70.0 > 75.0 > 80.0 > 85.0

-100

-100

-50

-50

0

0

50

50

100

100

150

150

200

200

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650

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850

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950

1000

1000

400

450

500

550

600

650

700

750

800

850

900

950

1000

1050

1100

1150


Building with one source façade (South)

G=0.5

G=0 at 50,100,150 m

G=0.5 Lw true

Lp meas (true)

Lp contours (true)


XL

N

W

S

E

Point Source (50m, South)


SUMMARY SHEET A9.2: Building Radiating From One facade Modelled by a Building With Equal Radiation

Model one façade smeared sources Measurement at 4 m height and at 50 m, 100 m, 150 m Contours at 50 m, 100 m, 250 m, 500 m, 1000 m, 2000 m Dimensions (m): 150 x 80 x 10



receiver height 4 m

Measure - source


Measure-ment points

100 250 500 1000 200050 South 19.2 11.6 7.6 12.9 9.6 50 North -12.1 -19.7 -23.7 -18.4 -21.750 East -1.9 -9.5 -13.5 -8.2 -11.550 West -1.9 -9.5 -13.5 -8.2 -11.550 Average 13.2 5.6 1.6 6.9 3.6

100 South 18.1 10.5 6.5 11.8 8.5 100 North -10.4 -18.0 -22.0 -16.7 -20.0100 East 0.5 -7.1 -11.1 -5.8 -9.1 100 West 0.5 -7.1 -11.1 -5.8 -9.1 100 Average 12.2 4.6 0.6 5.9 2.6 150 South 17.5 9.9 5.9 11.2 7.9 150 North -9.5 -17.1 -21.1 -15.8 -19.1150 East 1.5 -6.1 -10.1 -4.8 -8.1 150 West 1.5 -6.1 -10.1 -4.8 -8.1 150 Average 11.7 4.1 0.1 5.4 2.1


10 m high building Model using an industrial spectrum

Lw’’=90 dB/m² for South Façade




ground (G = 0.5)

-100

-100

-50

-50

0

0

50

50

100

100

150

150

200

200

250

250

300

300

350

350

400

400

450

450

500

500

550

550

600

600

650

650

700

700

750

750

800

800

850

850

900

900

950

950

1000

1000

400

450

500

550

600

650

700

750

800

850

900

950

1000

1050

1100

1150


-100

-100

-50

-50

0

0

50

50

100

100

150

150

200

200

250

250

300

300

350

350

400

400

450

450

500

500

550

550

600

600

650

650

700

700

750

750

800

800

850

850

900

900

950

950

1000

1000

400

450

500

550

600

650

700

750

800

850

900

950

1000

1050

1100

1150


Building with one source façade (South)

G=0.5

G=0 at 50,100,150m

G=0.5 Lw true

Lp meas (true)

Lp contours (true)


XL

N

W

S

E

Assume Building with smeared sources on each facade

APPENDIX 10:

Noise Modelling Summary Sheets – Two Buildings With Directional Radiation


SUMMARY SHEET A10.1: Two Buildings With One Building Radiating Noise From One Facade Modelled as One Building Radiating Noise From Each Facade

Model (150 x 170 x 10) one façade smeared sources Measurement at 4 m height and at 50 m, 100 m, 150 m Contours at 50 m, 100 m, 250 m, 500 m, 1000 m, 2000 m Dimensions (m) : 150 x 80 x 10

Summary of results in the East direction Error LpA Calc - LpA True


receiver height 4m

Measure - source



50 South -25.6 -22.3 -22.5 -22.7 -23.0 50 North -25.7 -22.4 -22.6 -22.8 -23.1 50 East -6.1 -2.8 -3.0 -3.2 -3.5 50 West -6.1 -2.8 -3.0 -3.2 -3.5 50 Average -9.1 -5.8 -6.0 -6.2 -6.5

100 South -22.5 -19.2 -19.4 -19.6 -19.9 100 North -22.8 -19.5 -19.7 -19.9 -20.2 100 East -7.5 -4.2 -4.4 -4.6 -4.9 100 West -7.5 -4.2 -4.4 -4.6 -4.9 100 Average -10.4 -7.1 -7.3 -7.5 -7.8 150 South -20.8 -17.5 -17.7 -17.9 -18.2 150 North -20.8 -17.5 -17.7 -17.9 -18.2 150 East -7.9 -4.6 -4.8 -5.0 -5.3 150 West -7.9 -4.6 -4.8 -5.0 -5.3 150 Average -10.7 -7.4 -7.6 -7.8 -8.1


10 m high buildings 10 m gap between the two buildings


Lw’’ = 90 dB/m² for South Façade

Brick Absorption coefficient α = 0.05 for the

building Max order of reflection = 5



Contours are calculated with CADNA for a mixed

ground (G=0.5) with barrier effect

��

-500

-500

-400

-400

-300

-300

-200

-200

-100

-100

0

0

100

100

200

200

300

300

400

400

500

500

600

600

700

700

800

800

500

600

700

800

900

1000

1100

1200

1300


G=0.5

G=0

at 50,100,150m

Lw true

Lw calc

E

S

W

N

XL

G=0.5

Lp contours (true)

Lp meas (true)

Lp contours (calc)

-600

-600

-500

-500

-400

-400

-300

-300

-200

-200

-100

-100

0

0

100

100

200

200

300

300

400

400

500

500

600

600

700

700

500

500

600

600

700

700

800

800

900

900

1000

1000

1100

1100

1200

1200

1300

1300

1400

1400


One source façade between 2 buildings Building with smeared source on each façade




Summary of results in the North direction Error LpA Calc - LpA True


receiver height 4 m

Measure - source


Measure-

ment points 100 250 500 1000 2000

50 South 0.0 -12.0 -15.4 -17.1 -4.3 50 North -0.1 -12.1 -15.5 -17.2 -4.4 50 East 19.5 7.5 4.1 2.4 15.2 50 West 19.5 7.5 4.1 2.4 15.2 50 Average 16.5 4.5 1.1 -0.6 12.2

100 South 3.1 -8.9 -12.3 -14.0 -1.2 100 North 2.8 -9.2 -12.6 -14.3 -1.5 100 East 18.1 6.1 2.7 1.0 13.8 100 West 18.1 6.1 2.7 1.0 13.8 100 Average 15.2 3.2 -0.2 -1.9 10.9 150 South 4.8 -7.2 -10.6 -12.3 0.5 150 North 4.8 -7.2 -10.6 -12.3 0.5 150 East 17.7 5.7 2.3 0.6 13.4 150 West 17.7 5.7 2.3 0.6 13.4 150 Average 14.9 2.9 -0.5 -2.2 10.6











��

-500

-500

-400

-400

-300

-300

-200

-200

-100

-100

0

0

100

100

200

200

300

300

400

400

500

500

600

600

700

700

800

800

500

600

700

800

900

1000

1100

1200

1300


G=0.5

G=0

at 50,100,150m

Lw true

Lw calc

E

S

W

N

XL

G=0.5

Lp contours (true)

Lp meas (true)

Lp contours (calc)

-600

-600

-500

-500

-400

-400

-300

-300

-200

-200

-100

-100

0

0

100

100

200

200

300

300

400

400

500

500

600

600

700

700

500

500

600

600

700

700

800

800

900

900

1000

1000

1100

1100

1200

1200

1300

1300

1400

1400






Summary of results in the South direction Error LpA Calc - LpA True


receiver height 4 m

Measure - source



50 South 0.6 -11.9 -14.8 -11.0 -13.0 50 North 0.5 -12.0 -14.9 -11.1 -13.1 50 East 20.1 7.6 4.7 8.5 6.5 50 West 20.1 7.6 4.7 8.5 6.5 50 Average 17.1 4.6 1.7 5.5 3.5

100 South 3.7 -8.8 -11.7 -7.9 -9.9 100 North 3.4 -9.1 -12.0 -8.2 -10.2 100 East 18.7 6.2 3.3 7.1 5.1 100 West 18.7 6.2 3.3 7.1 5.1 100 Average 15.8 3.3 0.4 4.2 2.2 150 South 5.4 -7.1 -10.0 -6.2 -8.2 150 North 5.4 -7.1 -10.0 -6.2 -8.2 150 East 18.3 5.8 2.9 6.7 4.7 150 West 18.3 5.8 2.9 6.7 4.7 150 Average 15.5 3.0 0.1 3.9 1.9











��

-500

-500

-400

-400

-300

-300

-200

-200

-100

-100

0

0

100

100

200

200

300

300

400

400

500

500

600

600

700

700

800

800

500

600

700

800

900

1000

1100

1200

1300



G=0.5

G=0.5

G=0

at 50,100,150m

Lw true

Lw calc XL

N

W

S

E

-600

-600

-500

-500

-400

-400

-300

-300

-200

-200

-100

-100

0

0

100

100

200

200

300

300

400

400

500

500

600

600

700

700

500

500

600

600

700

700

800

800

900

900

1000

1000

1100

1100

1200

1200

1300

1300

1400

1400


Lp contours (true)

Lp meas (true)

Lp contours (calc)


APPENDIX 11:

Noise Modelling Summary Sheets – Four Buildings With Directional Radiation


SUMMARY SHEET A11.1: Four Buildings With One Building Radiating Noise From One Facade Modelled as One Building Radiating Noise From Each Facade

Model (310*170*10) one façade smeared sources Measurement at 4 m height and at 50 m, 100 m, 150 m Contours at 50 m, 100 m, 250 m, 500 m, 1000 m, 2000 m Dimensions (m) : 150 x 80 x 10

Summary of results in the East direction


receiver height 4m

Measure - source


Measure-ment points 250 500 1000 2000

50 South -17.7 -20.5 -21.6 -22.5 50 North -17.6 -20.4 -21.5 -22.4 50 East -0.9 -3.7 -4.8 -5.7 50 West 5.7 2.9 1.8 0.9 50 Average 0.6 -2.2 -3.3 -4.2

100 South -15.5 -18.3 -19.4 -20.3 100 North -15.2 -18.0 -19.1 -20.0 100 East -2.8 -5.6 -6.7 -7.6 100 West 3.3 0.5 -0.6 -1.5 100 Average -1.7 -4.5 -5.6 -6.5 150 South -13.8 -16.6 -17.7 -18.6 150 North -13.3 -16.1 -17.2 -18.1 150 East -2.7 -5.5 -6.6 -7.5 150 West 2.2 -0.6 -1.7 -2.6 150 Average -2.4 -5.2 -6.3 -7.2


10 m high buildings 10 m gap between the four buildings









-700

-700

-600

-600

-500

-500

-400

-400

-300

-300

-200

-200

-100

-100

0

0

100

100

200

200

300

300

400

400

500

500

600

600

700

700

800

800

900

900

1000

1000

300

300

400

400

500

500

600

600

700

700

800

800

900

900

1000

1000

1100

1100

1200

1200

1300

1300

1400

1400


��

-600

-600

-500

-500

-400

-400

-300

-300

-200

-200

-100

-100

0

0

100

100

200

200

300

300

400

400

500

500

600

600

700

700

800

800

900

900

1000

1000

1100

1100

300 30

0 400 40

0 500 50

0 600 60

0 700 70

0 800 80

0 900 90

0 1000 10

00 1100 11

00 1200 12

00 1300 13

00 1400 14

00


G=0.5

Lp contours (true)

Lp meas (true)

Lw true

G=0

at 50,100,150m

Lw calc XL

G=0.5

E

S

W

N

Lp contours (calc)

One source façade between four buildings Smeared sources on each facade




Summary of results in the North direction

Error LpA Calc - LpA True


receiver height 4m

Measure -

source distance, m (to side of building)

Measure-

ment points 250 500 1000 2000

50 South -17.5 -18.4 -21.8 -24.4 50 North -17.4 -18.3 -21.7 -24.3 50 East -0.7 -1.6 -5.0 -7.6 50 West 5.9 5.0 1.6 -1.0 50 Average 0.8 -0.1 -3.5 -6.1

100 South -15.3 -16.2 -19.6 -22.2 100 North -15.0 -15.9 -19.3 -21.9 100 East -2.6 -3.5 -6.9 -9.5 100 West 3.5 2.6 -0.8 -3.4 100 Average -1.5 -2.4 -5.8 -8.4 150 South -13.6 -14.5 -17.9 -20.5 150 North -13.1 -14.0 -17.4 -20.0 150 East -2.5 -3.4 -6.8 -9.4 150 West 2.4 1.5 -1.9 -4.5 150 Average -2.2 -3.1 -6.5 -9.1


10 m high buildings 10 m gap between the four buildings









-700

-700

-600

-600

-500

-500

-400

-400

-300

-300

-200

-200

-100

-100

0

0

100

100

200

200

300

300

400

400

500

500

600

600

700

700

800

800

900

900

1000

1000

300

300

400

400

500

500

600

600

700

700

800

800

900

900

1000

1000

1100

1100

1200

1200

1300

1300

1400

1400


��

-600

-500

-500

-400

-400

-300

-300

-200

-200

-100

-100

0

0

100

100

200

200

300

300

400

400

500

500

600

600

700

700

800

800

900

900

1000

1000

1100

1100

300 30

0 400 40

0 500 50

0 600 60

0 700 70

0 800 80

0 900 90

0 1000 10

00 1100 11

00 1200 12

00 1300 13

00 1400 14

00


G=0.5

G=0.5

Lp contours (true)

Lp meas (true)

Lw true

G=0

at 50,100,150m

Lw calc XL

E

S

W

N

Lp contours (calc)

-600 One source façade between four buildings Smeared sources on each facade




Summary of results in the South direction Error LpA Calc - LpA True


receiver height 4 m

Measure - source



50 South 0.6 -11.9 -14.8 -11.0 -13.0 50 North 0.5 -12.0 -14.9 -11.1 -13.1 50 East 20.1 7.6 4.7 8.5 6.5 50 West 20.1 7.6 4.7 8.5 6.5 50 Average 17.1 4.6 1.7 5.5 3.5

100 South 3.7 -8.8 -11.7 -7.9 -9.9 100 North 3.4 -9.1 -12.0 -8.2 -10.2 100 East 18.7 6.2 3.3 7.1 5.1 100 West 18.7 6.2 3.3 7.1 5.1 100 Average 15.8 3.3 0.4 4.2 2.2 150 South 5.4 -7.1 -10.0 -6.2 -8.2 150 North 5.4 -7.1 -10.0 -6.2 -8.2 150 East 18.3 5.8 2.9 6.7 4.7 150 West 18.3 5.8 2.9 6.7 4.7 150 Average 15.5 3.0 0.1 3.9 1.9











��

-500

-500

-400

-400

-300

-300

-200

-200

-100

-100

0

0

100

100

200

200

300

300

400

400

500

500

600

600

700

700

800

800

500

600

700

800

900

1000

1100

1200

1300



G=0.5

G=0.5

G=0

at 50,100,150m

Lw true

Lw calc XL

N

W

S

E

-600

-600

-500

-500

-400

-400

-300

-300

-200

-200

-100

-100

0

0

100

100

200

200

300

300

400

400

500

500

600

600

700

700

500

500

600

600

700

700

800

800

900

900

1000

1000

1100

1100

1200

1200

1300

1300

1400

1400


Lp contours (true)

Lp meas (true)

Lp contours (calc)


APPENDIX 12:

Noise Modelling Summary Sheets – Point Source Between Buildings


G=0.5

SUMMARY SHEET A12.1: Point Source Between Two Buildings Modelled as One Building Radiating Noise From Each Facade

Model (310 x 80 x 10) Measurement at 4 m height and at 50 m, 100 m, 150 m Contours at 50 m, 100 m, 250 m, 500 m, 1000 m, 2000 m Dimensions (m) : 150 x 80 x 10



receiver height 4 m

Measure - source



Measure-

ment points 250 500 1000 2000

50 500 1 short -5.7 -12.7 -1.1 -5.1 50 500 1 long 9.4 2.5 14.1 10.1 50 500 Average 6.5 -0.4 11.2 7.2 50 Full 1 short -5.8 -12.8 -1.3 -4.7 50 Full 1 long 9.6 2.3 13.4 9.5 50 Full Average 6.7 -0.6 10.5 6.7

100 500 1 short -3.9 -10.9 0.7 -3.3 100 500 1 long 9.2 2.3 13.9 9.9 100 500 Average 6.4 -0.5 11.1 7.1 100 Full 1 short -3.9 -10.9 0.7 -3.3 100 Full 1 long 9.6 2.3 13.4 9.5 100 Full Average 6.8 -0.5 10.6 6.7 150 500 1 short -2.8 -9.8 1.8 -2.2 150 500 1 long 9.2 2.3 13.9 9.9 150 500 Average 6.5 -0.5 11.1 7.1 150 Full 1 short -2.8 -9.8 1.8 -2.2 150 Full 1 long 9.6 2.3 13.4 9.5 150 Full Average 6.8 -0.5 10.7 6.8



Point Source at 5 m high between two buildings




buildings Max order of reflection = 2





ground (G = 0.5)

-450

-450

-400

-400

-350

-350

-300

-300

-250

-250

-200

-200

-150

-150

-100

-100

-50

-50

0

0

50

50

100

100

150

150

200

200

250

250

300

300

350

350

400

400

450

450

500

500

550

550

600

600

650

650

700

700

750

750

800

800

500

500

550

550

600

600

650

650

700

700

750

750

800

800

850

850

900

900

950

950

1000

1000

1050

1050

1100

1100

1150

1150

1200

1200

1250

1250

1300

1300

1350

1350


��

-250

-250

-200

-200

-150

-150

-100

-100

-50

-50

0

0

50

50

100

100

150

150

200

200

250

250

300

300

350

350

400

400

450

450

500

500

700

700

750

750

800

800

850

850

900

900

950

950

1000

1000

1050

1050

1100

1100

1150

1150

1200

1200


G=0.5

Lw true Lp contours (true)

G=0

at 50,100,150m

Lw calc XL

Lp meas (true)

Lp contours (calc)

Point Source between Two Buildings Smeared sources on each facade


APPENDIX 13:

Noise Modelling Summary Sheets – Point Source on Roof of Building



SUMMARY SHEET A13.1: Point Source on the Roof of a Building Modelled as a Building Radiating Noise From Each Facade

Model Measurement at 1.5 m height and 50,100,150 m Contours at 50 m, 100 m, 250 m, 500 m, 1000 m, 2000 m Dimensions (m) : 150 x 80 x 10


receiver height 4m

Measure - source


Back calc Lw using

500 Hz


50 500 1 short 7.9 -2.1 -2 -1.2 -0.9 50 500 1 long 2.7 -7.4 -7.3 -6.5 -6.2 50 500 Average 6.0 -3.9 -3.9 -3.1 -2.8 50 Full 1 short 1.9 -8.4 -8.4 -7.5 -6.6 50 Full 1 long 2.7 -7.6 -7.6 -6.7 -5.9 50 Full Average 2.3 -7.9 -7.9 -7.1 -6.2 100 500 1 short 5.8 -4.2 -4.1 -3.3 -3 100 500 1 long 6.2 -3.8 -3.7 -2.9 -2.6 100 500 Average 6 -4 -3.9 -3.1 -2.8 100 Full 1 short 5.7 -4.7 -4.8 -4.1 -3.5 100 Full 1 long 6.2 -4.2 -4.3 -3.7 -3.1 100 Full Average 5.9 -4.4 -4.5 -3.9 -3.3 150 500 1 short 7.4 -2.6 -2.5 -1.7 -1.4 150 500 1 long 7.4 -2.6 -2.5 -1.7 -1.4 150 500 Average 7.4 -2.6 -2.5 -1.7 -1.4 150 Full 1 short 7.7 -2.8 -3.1 -2.5 -2.2 150 Full 1 long 7.7 -2.8 -3.1 -2.5 -2.2 150 Full Average 7.7 -2.8 -3.1 -2.5 -2.2


10 m high buildings Model using a falling spectrum






ground (G = 0.5)

-100

-100

-50

-50

0

0

50

50

100

100

150

150

200

200

250

250

300

300

350

350

400

400

800

800

850

850

900

900

950

950

1000

1000

1050

1050

1100

1100


-100

-50

-50

0

0

50

50

100

100

150

150

200

200

250

250

300

300

350

350

400

400

750

750

800

800

850

850

900

900

950

950

1000

1000

1050

1050

1100

1100


Point Source on the Roof of the Building Smeared sources on each facade

Long

Short

G=0.5

G=0.5

G=0

at 50,100,150m (4m and 1.5m)

Lw true

Lp meas (true)

Lp contours (true)


XL


SUMMARY SHEET A13.1: Point Source on the Roof of a Building Modelled as a Building Radiating Noise From Each Facade

Model Measurement at 4 m height and 50,100,150 m Contours at 50 m, 100 m, 250 m, 500 m, 1000 m, 2000 m Dimensions (m) : 150 x 80 x 10


receiver height 4 m

Measure - source


Back calc Lw using

500 Hz


50 500 1 short 4.3 -5.7 -5.6 -4.8 -4.5 50 500 1 long 4.6 -5.4 -5.3 -4.5 -4.2 50 500 Average 4.5 -5.5 -5.4 -4.6 -4.3 50 Full 1 short 4.3 -6.0 -6.0 -5.2 -4.5 50 Full 1 long 4.4 -5.9 -6.0 -5.2 -4.5 50 Full Average 4.4 -5.9 -6.0 -5.2 -4.5

100 500 1 short 7.2 -2.8 -2.7 -1.9 -1.6 100 500 1 long 7.3 -2.7 -2.6 -1.8 -1.5 100 500 Average 7.3 -2.7 -2.6 -1.8 -1.5 100 Full 1 short 7.2 -3.3 -3.5 -2.9 -2.5 100 Full 1 long 7.2 -3.3 -3.5 -2.9 -2.5 100 Full Average 7.2 -3.3 -3.5 -2.9 -2.5 150 500 1 short 7.9 -2.1 -2.0 -1.2 -0.9 150 500 1 long 7.9 -2.1 -2.0 -1.2 -0.9 150 500 Average 7.9 -2.1 -2.0 -1.2 -0.9 150 Full 1 short 7.9 -2.1 -2.0 -1.2 -0.9 150 Full 1 long 8.3 -2.4 -2.7 -2.3 -2.0 150 Full Average 8.3 -2.4 -2.7 -2.3 -2.0


10 m high buildings Model using a Falling spectrum






ground (G = 0.5)

-100

-100

-50

-50

0

0

50

50

100

100

150

150

200

200

250

250

300

300

350

350

400

400

800 80

0

850 85

0

900 90

0

950 95

0

1000 10

00

1050 10

50

1100 11

00


-100

-100

-50

-50

0

0

50

50

100

100

150

150

200

200

250

250

300

300

350

350

400

400

750

750

800

800

850

850

900

900

950

950

1000

1000

1050

1050

1100

1100


Point Source on the Roof of the Building Smeared sources on each facade

Long

Short

G=0.5

G=0.5

G=0

at 50,100,150m (4m and 1.5m)

Lw true

Lp meas (true)

Lp contours (true)


XL

APPENDIX 14:

Noise Modelling Summary Sheets – Point Source on Stack


SUMMARY SHEET A14.1: Stack with a Point Source on the Top Modelled as a Stack With a Point Source at 4m

Stack height, diameter: h=50m, ∅=3m h=100m, ∅=6m

+ Point Source on the top + Point source at 4 m high Measurements at 4 m height and at 50 m, 100 m, 150 m Contours at 50 m, 100 m, 250 m, 500 m, 1000 m, 2000 m

Summary of results


receiver height 4 m Source

height, m

Measure - source

distance, m


100 250 500 1000 200050 50 500 -4.7 -9.7 -11.0 -12.2 -14.250 50 Full -4.9 -9.9 -10.9 -11.6 -12.450 100 500 0.2 -4.8 -6.1 -7.3 -9.3 50 100 Full -0.2 -5.4 -6.6 -7.6 -8.7 50 150 500 2.9 -2.1 -3.4 -4.6 -6.6 50 150 Full 2.7 -2.6 -3.9 -5.0 -6.4 100 50 500 -3.5 -9.8 -12.9 -15.1 -17.3100 50 Full -3.7 -10 -12.7 -14.4 -15.4100 100 500 0.1 -6.2 -9.3 -11.5 -13.7100 100 Full -0.2 -6.5 -9.2 -10.9 -11.9100 150 500 2.9 -3.4 -6.5 -8.7 -10.9100 150 Full 2.6 -3.8 -6.6 -8.5 -9.6

Calculation configu

Models usin Lw = 90 dB f

No reflection

Back-calcula

0), without bspectrum

Contours ca

ground (G = Directivity: A

exhaust Gasm/s), wind v

G=0 Top at 50,100,150m

G=0.5 Top

Lw calc

Lw true

m

Lp contours (true)

Lp meas (true)

Lp contours (calc)

Source on the top (reality) Source at stack centre

AT5414/2 Rev 1

G=0.5 4

ra

g I

or

tioarr

lcu 0.

uto T

elo

lo

XL

tion

ndustrial spectrum

the Point source

n done for hard ground (G = ier effect, for 500 Hz and full

lated with CADNA for mixed 5) without barrier effect

matic direction “Chimney”, emp (200 °C), exit velocity (30 city (3 m/s)

cation at 4m (calculated)

Acoustic Technology

APPENDIX 15:

Noise Modelling Summary Sheets – Industrial Zone



SUMMARY SHEET A15.1: Industrial Zone – Model Set-up

The Industrial Zone Cadna model is summarised below. Industrial Zone CADNA Model - Layout

Vertical Area Source “Main Warehouse” Lw’’ = 85.1 dBA

sources on each façade “Assembly” Lw’’ = 88.2 dBA

Sources on each façade “Main Factory” Lw’’ = 91.4 dBA

Point Source “Power Station” Lw = 122 dBA

Point Source “Conveyor” Lw = 106 dBA

Point Source Roof “Design Office” Lw = 50 dBA

Point Source “Generator” Lw = 108 dBA

Point Source “Chimney” Lw = 125 dBA

Sources on each façade “Control Room” Lw’’ = 90.7 dBA

Point Source “Product stock” Lw = 110 dBA

Cont/…


Sound Power Level (L w) Setup

Point Source Lw Generator 108 Conveyor 106 Power station source 122 Chimney source 125 Design Office source 90 Finished product stock 110 Total 127 Area Source Lw'' Lw Main Factory 91 126 Assembly 88 126 Control Room 91 126 Total 95 130 Vertical Area Source Lw’’ Lw Main Factory 91 123 Assembly 88 122 Control Room 91 124 Main Warehouse 85 108 Total 96 128 TOTAL Point Sources 127 Area Sources 130 Vertical Area Sources 128

TOTAL Lw 134 dB(A)


SUMMARY SHEET A15.2: Industrial Zone Modelled by One Point Source Using

Hemispherical Method for Sound Power Determination

industrial zone Point source Measurement at 4 m height and at 500 m, 1000 m, 2000 m Contours at 500 m, 1000 m, 2000 m Method used for the calculations Back calculation with XL using the Hemispherical method (ISO 9613-2)


Where Adiv = 10log(2πr2) : Attenuation due to geometrical divergence Aatm = (αf .r) /1000 : attenuation due to atmospheric absorption

r is the distance from the source to the receiver, in metres αf is the atmospheric attenuation coefficient, in decibels per kilometre


Lp measurement are calculated with CADNA for hard ground (G = 0) inside and outside the plant area with barrier effect and 5 orders of reflection

Contours are calculated with CADNA for

hard ground (G = 0) inside the plant area and mixed ground outside the plant area (G = 0.5) a single band (500 Hz) with barrier effect and 5 orders of reflection

G=0.5

G=0.5

G=0 at 500,1000,2000m

Lw true

Lp meas (true)

Lp contours (true)


XL

Cont/…


Receivers at 500m, 1000m and 2000m from the centre for the calculations of the contours

Model with CADNA

Point Source

Cont/…

North


Results for a Point Source model using the Hemispherical method

Error LpA Calc - LpA True (receiver height 4 m)

Contours distance from

centre, m

Measurementdistance from

centre, m

Measurement point

location North South East West 500 500 North -0.9 -0.9 0 1.5 500 500 South 1.3 1.3 2.2 3.7 500 500 East 0.2 0.2 1.1 2.6 500 500 West -4.6 -4.6 -3.7 -2.2 500 1000 North -1.9 -1.9 -1.0 0.5 500 1000 South 1.5 1.5 2.4 3.9 500 1000 East 0.0 0.0 0.9 2.4 500 1000 West -4.4 -4.4 -3.5 -2.0 500 2000 North -2.5 -2.5 -1.6 -0.1 500 2000 South 1.4 1.4 2.3 3.8 500 2000 East -0.7 -0.7 0.2 1.7 500 2000 West -3.9 -3.9 -3.0 -1.5 1000 500 North -0.1 -0.3 0.9 1.6 1000 500 South 2.1 1.9 3.1 3.8 1000 500 East 1.0 0.8 2.0 2.7 1000 500 West -3.8 -4.0 -2.8 -2.1 1000 1000 North -1.1 -1.3 -0.1 0.6 1000 1000 South 2.3 2.1 3.3 4.0 1000 1000 East 0.8 0.6 1.8 2.5 1000 1000 West -3.6 -3.8 -2.6 -1.9 1000 2000 North -1.7 -1.9 -0.7 0.0 1000 2000 South 2.2 2.0 3.2 3.9 1000 2000 East 0.1 -0.1 1.1 1.8 1000 2000 West -3.1 -3.3 -2.1 -1.4 2000 500 North 0.3 0 1.6 1.1 2000 500 South 2.5 2.2 3.8 3.3 2000 500 East 1.4 1.1 2.7 2.2 2000 500 West -3.4 -3.7 -2.1 -2.6 2000 1000 North -0.7 -1.0 0.6 0.1 2000 1000 South 2.7 2.4 4.0 3.5 2000 1000 East 1.2 0.9 2.5 2.0 2000 1000 West -3.2 -3.5 -1.9 -2.4 2000 2000 North -1.3 -1.6 0.0 -0.5 2000 2000 South 2.6 2.3 3.9 3.4 2000 2000 East 0.5 0.2 1.8 1.3 2000 2000 West -2.7 -3.0 -1.4 -1.9


SUMMARY SHEET A15.3: Industrial Zone Modelled by One Point Source Using Stuber

Method for Sound Power Determination

industrial zone Point source Measurement all around the plant area at 4 m height Contours at 528 m from the centre Method used for the calculations Back calculation with XL using the Stüber method using the standard BS ISO 8297 : 1994

Lw = Lpaverage + ∆Ls + ∆Lα + ∆Lf Where ∆Ls = 10log((2Sm+h.l)/S0) : area term

∆Lα = 0.5*α√Sm : atmospheric absorption ∆Lf = log (d/(4√ Sp) : proximity correction

Sm is the measurement area in squares metres h is the microphone height, in metres l is the length of the measurement contour, metres α is the sound attenuation coefficient through air, in decibels per metre d is the Measurement distance, in metres





G=0.5

G=0.5

G=0, receivers all around the plant area

Lw true

Lp meas (true)

Lp contours (true)


XL

Cont/…


Dimensions: L (m) 352 Largest Dimension of Plant area Sm (m2) 80242 Measurement Area l (m) 1140 2D length Sp (m2) 53050 Plant Area d (m) 25 Average measurement distance Dm 40.71 Distance between measurement position (Dm<2d) 28.00 Measurement Points "d" condition 11.5 < d < 35

1.5*L 528 Contours Distance H 13.2 Height of the plant

Cont/…


Receivers at 528m from the centre for the calculations of Contours

Model with CADNA

Point Source

Cont/…

North


Results for a Point Source model using the Stüber method

with receivers set at 528m from the centre


receiver height 4 m Contours distance

from centre, m

Back calc Lw using full octave

or 500 Hz North South East West 528 full -0.6 -0.7 -2 -3.9 528 500 1.9 2 3.3 5.2


SUMMARY SHEET A15.4: Industrial Zone Modelled by 2D Area Source Using Hemispherical


industrial zone 2D area source Measurement at 4 m height and at 500 m, 1000 m, 2000 m Contours at 500 m, 1000 m, 2000 m Method used for the calculations Back calculation with XL using the Hemispherical method (ISO 9613-2)


Where Adiv = 10log(2πr2) : Attenuation due to geometrical divergence Aatm = (αf .r) /1000 : attenuation due to atmospheric absorption






G=0.5

G=0.5

G=0 at 500,1000,2000m

Lw true

Lp meas (true)

Lp contours (true)


XL

Cont/…


Receivers at 500m, 1000m and 2000m from the centre for the calculations of the contours

Model with CADNA

2D area source

Cont/…

North


Results for a 2D area Source model using the Hemispherical method

Error LpA Calc - LpA True (receiver height 4 m)


centre, m

Measurement distance from

centre, m

Measurement point

location North South East West 500 500 North -3.1 -2 -2.8 0.9 500 500 South -0.9 0.2 -0.6 3.1 500 500 East -2.0 -0.9 -1.7 2.0 500 500 West -6.8 -5.7 -6.5 -2.8 500 1000 North -4.1 -3.0 -3.8 -0.1 500 1000 South -0.7 0.4 -0.4 3.3 500 1000 East -2.2 -1.1 -1.9 1.8 500 1000 West -6.6 -5.5 -6.3 -2.6 500 2000 North -6.6 -5.5 -6.3 -2.6 500 2000 South -0.8 0.3 -0.5 3.2 500 2000 East -2.9 -1.8 -2.6 1.1 500 2000 West -6.1 -5.0 -5.8 -2.1 1000 500 North -2.2 -1.1 -1.6 0.9 1000 500 South 0.0 1.1 0.6 3.1 1000 500 East -1.1 0.0 -0.5 2.0 1000 500 West -5.9 -4.8 -5.3 -2.8 1000 1000 North -3.2 -2.1 -2.6 -0.1 1000 1000 South 0.2 1.3 0.8 3.3 1000 1000 East -1.3 -0.2 -0.7 1.8 1000 1000 West -5.7 -4.6 -5.1 -2.6 1000 2000 North -5.7 -4.6 -5.1 -2.6 1000 2000 South 0.1 1.2 0.7 3.2 1000 2000 East -2.0 -0.9 -1.4 1.1 1000 2000 West -5.2 -4.1 -4.6 -2.1 2000 500 North -1.4 -0.5 -0.6 0.3 2000 500 South 0.8 1.7 1.6 2.5 2000 500 East -0.3 0.6 0.5 1.4 2000 500 West -5.1 -4.2 -4.3 -3.4 2000 1000 North -2.4 -1.5 -1.6 -0.7 2000 1000 South 1.0 1.9 1.8 2.7 2000 1000 East -0.5 0.4 0.3 1.2 2000 1000 West -4.9 -4.0 -4.1 -3.2 2000 500 North -0.3 0.6 0.5 1.4 2000 500 South -5.1 -4.2 -4.3 -3.4 2000 1000 East -2.4 -1.5 -1.6 -0.7 2000 1000 West 1.0 1.9 1.8 2.7


SUMMARY SHEET A15.5: Industrial Zone Modelled by 2D Area Source Using Stüber Method

for Sound Power Determination

industrial zone 2D area source Measurement all around the plant area at 4 m height Contours at 528 m from the centre Method used for the calculations Back calculation with XL using the Stüber method using the standard BS ISO 8297 : 1994





Lp measurements are calculated with CADNA for hard ground (G = 0) inside and outside the plant area with barrier effect (C1 = 3) and 5 order of reflection



Dimensions: L (m) 352 Largest Dimension of Plant area Sm (m2) 80242 Measurement Area

G=0.5

G=0.5

G=0, receivers all around the plant area

Lw true

Lp meas (true)

Lp contours (true)


XL

Cont/…


l (m) 1140 2D length Sp (m2) 53050 Plant Area d (m) 25 Average measurement distance Dm 40.71 Distance between measurement position (Dm<2d) 28.00 Measurement Points "d" condition 11.5 < d < 35

1.5*L 528 Contours Distance H 13.2 Height of the plant

Cont/…


Receivers at 528m from the centre for the calculations of the contours

Model with CADNA

2D area source

Cont/…

North


Results for a 2D area Source model using the Stüber method with receivers set at 528m from the centre

Error LpA Calc - LpA True receiver height 4 m


centre, m

Back calc Lw using full octave

or 500 Hz North South East West 528 full -1.6 -0.4 -0.7 3.6 528 500 -0.7 0.9 0.5 4.6


APPENDIX 16:

Noise Modelling Summary Sheets – Open Site

SUMMARY SHEET 16.1: Open Site - Model Set-up

The Open Site Cadna model is summarised below. Open Site CADNA Model - Layout Industrial Site Model with CADNA with receivers all around the plant area for the Stüber Method

Dm

Measurement area

Plant Area, G = 0

…

AT5414/2 Rev 1 Acou

Cont/

stic Technology

Sound Power Level (L w) Setup

Point Sources Name Lw, dB(A) Gas out from separator 2 (valve) 58.3 Main flare gas KO pot 62.2 Gas out from separator 1 (valve) 83.4 Gas turbine B exhaust 73.4 Gas turbine B ventilation (turbine inlet) 79 Gas turbine B ventilation (turbine extract) 82.3 Gas turbine B ventilation (alternator inlet) 74.5 Water injection pump B 86.8 Dehydration unit 83.3 Compressor A coolant pipes & pumps 89.9 Compressor B coolant pipes & pumps 93.7 Gas pipe valve for pilot flare 81.3 Vent gas KO pot 61.9 Flare gas control panel 62.9 Oil pump B 85.6 Gas turbine A air filter 82.9 Gas turbine A fan unit 82.3 Gas turbine A exhaust 70.5 Gas turbine A ventilation (turbine inlet) 79.1 Gas turbine A ventilation (turbine extract) 84.2 10-v39 KO pot 84.9 Gas turbine A ventilation (alternator extract) 82.8 Gas turbine A ventilation (alternator inlet) 73.9 Gas turbine B air filter 93.1 Gas turbine B fan unit 80.4 Inlet valve from separator 2 69.7 Inlet valve from separator 1 73.2 Gas turbine A 87.5 Gas turbine B 89.2 Centre Point Source 89.2 Total: 100.3

Area Sources Name Lw, dB(A) Lw’’, dB(A)/m2 LP Heater (top side) 68.6 53.8 HP Heater (top side) 66 50.8 Flare (top) 79.6 61 dbsum() 80.1

…

AT5414/2 Rev 1 Acousti

Cont/

c Technology

Line Sources

Name Lw, dB(A) Lw’, dB(A)/m Lift gas pipe from compressor house 90.2 70.7 Flare gas pipe from separator 1 95.1 86.8 Oil pipe from pump to coalesce drum 87.6 77.3 Flare gas pipe from separator 1 90.9 86.8 HP gas pipe (imported) 82.7 69.5 Produced gas pipe from KO pot to gas turbine generators 82.6 63.4 Flare gas pipe (2nd section to KO pot)) 82.3 71.2 Gas pipe from separator 1 to compressor house 89.7 75.1 Flare gas pipe (3rd section) 80.7 66.7 Flare gas pipe (4th section) 79.5 62.2 Oil pipe from separator 3 to oil pump 78 69.8 Gas pipe from separator 1 to compressor house 86.4 75.1 Lift gas pipe export to site C 75.1 61.8 Gas pipe from compressors to KO pot 75.1 63.4 Produced water pipe from separator 1 78.6 68.4 HP gas pipe from site C to HP heater (first section) 72.3 58 HP gas pipe imported from site C 71.9 58.4 Processed oil pipe from oil pump (2nd section) 71.7 53.7 LP gas pipe to LP heater 70.9 54.1 Oil pipe from coalesce drum to oil pump 70.3 59.5 HP gas pipe to HP heater 72.3 55.1 Produced water pipe from separator 2 70.6 62.3 Flare gas pipe from separator 2 76.3 65.3 HP gas pipe from site C to HP heater 68.4 58 LP gas pipe from site C to LP heater 68.3 50.5 Produced water pipe to produced water tank 71 52.7 Produced water pipe from separator 2 68.4 62.3 Gas pipe from separator 2 to compressor house 68.8 57 Processed oil pipe from oil pump (1st section) 64.8 53.7 Produced oil pipe (output) 64.6 51.1 LP gas pipe imported from site C 64.6 51.3 LP gas pipe (imported) 64.3 51.1 Gas injection pipe 63.9 50.5 Gas injection pipe to site C 63.8 50.5 Flare gas pipe from separator 2 69.3 65.3 LP gas pipe from LP heater to separator 2 (1st section) 66.1 50.4 Flare gas pipe (1st section - along main pipe rack) 94.5 75.7 LP gas pipe from LP heater to separator 2 (2nd section) 58.6 50.4 HP gas pipe from site C to HP heater (2nd section) 64.7 50.7 HP gas pipe from HP heater to separator 1 65.7 50 HP gas pipe from HP heater to separator 1 58.3 50 Total: 100.6


Vertical Area Sources Name Lw, dB(A) Lw’’, dB(A)/m2 Compressor house double doors 78.4 66.6 Compressor house vent 1 67.2 67.9 Compressor house vent 2 66.8 67.6 Compressor house vent 3 69.7 70.4 Compressor house single door (north side) 57.8 55.3 LP heater (west side) 75 58.5 LP heater (north side) 65.9 53.6 LP heater (east side) 86.9 70.4 LP heater (south side) 79.2 66.9 HP heater (north side) 68.6 55.9 HP heater (east side) 69 52.4 HP heater (south side) 62.5 49.8 HP heater (west side) 71.3 54.7 Flare (east side) 79.6 67.7 Flare (south side) 79.6 69.3 Flare (west side) 79.6 67.7 Flare (north side) 79.6 69.3 Separator 1 (east side) 83.4 71.5 Separator 1 (south side) 83.4 76.2 Separator 2 (east side) 75.6 63.8 Separator 1 (north side) 83.4 76.2 Separator 2 (north side) 75.6 68.5 Separator 2 (south side) 75.6 68.5 Separator 2 (west side) 75.6 63.8 Separator 1 (west side) 83.4 71.5 Separator 3 (north side) 73 65.8 Separator 3 (west side) 73 61.1 Separator 3 (south side) 73 65.8 Separator 3 (east side) 73 61.1 Coalesce drum (west side) 78.3 68.7 Coalesce drum (south side) 78.3 70.5 Coalesce drum (east side) 78.3 68.7 Coalesce drum (north side) 78.3 70.5 Compressor house vent 2 66.8 67.6 Compressor house vent 2 66.8 67.6 dbsum() 93.9 TOTAL Sound Power Level Total Point Sources 100.3 Total Line Sources 100.6 Total Area Sources 80.1 Total Vertical Area Sources 93.9 TOTAL Lw, dB(A) 103.9


SUMMARY SHEET 16.2: Open Industrial Site Modelled as a 2D Area Source Using


Industrial Site 2D Area source Measurement at 4 m height and at 300 m from site centre Contours at 500 m, 1000 m, 2000 m Method used for the calculations

XL Lp contours (calc)

Lw calc

Lp contours (true)

Lp meas (true)

Lw true

G=0 or G=1 at 300m

G=1

G=1

Back calculation with XL using the Hemispherical method (ISO 9613-2)


Where Adiv = 10log(2πr2) : Attenuation due to geometrical divergence Aatm = (αf.r) /1000 : attenuation due to atmospheric absorption


Calculation configuration :

Lp measurements are calculated with CADNA for - hard ground (G = 0) inside plant area and G = 0 or 1 outside the plant area - with barrier effect and 5 orders of reflection

Contours are calculated with CADNA for - hard ground (G = 0) inside the plant area - soft ground (G = 1) outside the plant area - single band (500 Hz) - with barrier effect and 5 orders of reflection

…

AT5414/2 Rev 1 Acou

Cont/

stic Technology

Results for a 2D Area Source model with the Hemispherical method

Real site with contour line, G=1 outside the Measurement Area



at distances from centre, m, receiver height 4 m

Error LpA Calc - LpA True at distances from centre, m,

receiver height 4 m Contours distance,

m Measurement

points North South East West

Contours distance,

m Measurement

points North South East West500 North 300 m -4.5 -7.5 -5.7 -6.9 500 North 300 m -1.3 -4.3 -2.5 -3.7500 South 300 m -1.4 -4.4 -2.6 -3.8 500 South 300 m 1.5 -1.5 0.3 -0.9500 East 300 m 1 -2 -0.2 -1.4 500 East 300 m 3.7 0.7 2.5 1.3500 West 300 m -4.1 -7.1 -5.3 -6.5 500 West 300 m -1.4 -4.4 -2.6 -3.81000 North 300 m -4.3 -2.4 -4.1 -3 1000 North 300 m -1.1 0.8 -0.9 0.21000 South 300 m -1.2 0.7 -1 0.1 1000 South 300 m 1.7 3.6 1.9 3 1000 East 300 m 1.2 3.1 1.4 2.5 1000 East 300 m 3.9 5.8 4.1 5.21000 West 300 m -3.9 -2 -3.7 -2.6 1000 West 300 m -1.2 0.7 -1 0.12000 North 300 m -4.5 -0.6 -5.6 2.8 2000 North 300m -1.3 2.6 -2.4 6 2000 South 300 m -1.4 2.5 -2.5 5.9 2000 South 300 m 1.5 5.4 0.4 8.82000 East 300 m 1 4.9 -0.1 8.3 2000 East 300 m 3.7 7.6 2.6 11 2000 West 300 m -4.1 -0.2 -5.2 3.2 2000 West 300 m -1.4 2.5 -2.5 5.9

Flat area, G=1 outside the measurement area





receiver height 4 m Contours distance,

m Measurement


Contours distance,

m Measurement

points North South East West500 North 300 m -1.9 -1.4 -3.6 -3.5 500 North 300 m 1.4 1.9 -0.3 -0.2500 South 300 m -1.6 -1.1 -3.3 -3.2 500 South 300 m 1.4 1.9 -0.3 -0.2500 East 300 m 1.6 2.1 -0.1 0 500 East 300 m 4.5 5 2.8 2.9 500 West 300 m 0.1 0.6 -1.6 -1.5 500 West 300 m 2.7 3.2 1 1.1 1000 North 300 m -1.2 2.1 -2.1 -2.4 1000 North 300 m 2.1 5.4 1.2 0.9 1000 South 300 m -0.9 2.4 -1.8 -2.1 1000 South 300 m 2.1 5.4 1.2 0.9 1000 East 300 m 2.3 5.6 1.4 1.1 1000 East 300 m 5.2 8.5 4.3 4 1000 West 300 m 0.8 4.1 -0.1 -0.4 1000 West 300 m 3.4 6.7 2.5 2.2 2000 North 300 m -0.1 4.6 -2.2 5.8 2000 North 300 m 3.2 7.9 1.1 9.1 2000 South 300 m 0.2 4.9 -1.9 6.1 2000 South 300 m 3.2 7.9 1.1 9.1 2000 East 300 m 3.4 8.1 1.3 9.3 2000 East 300 m 6.3 11 4.2 12.22000 West 300 m 1.9 6.6 -0.2 7.8 2000 West 300 m 4.5 9.2 2.4 10.4


SUMMARY SHEET 16.3: Open Industrial Site Modelled as a 2D Area Source Using


Industrial Site 2D Area source Measurement at 4 m height and at 500 m, 1000 m, 2000 m from site centre Contours at 500 m, 1000 m, 2000 m Method used for the calculations

G=1 Lp contours (true)

Lp meas (true)

Lw true

G=0 or G=1 at 500, 1000, 2000 m

Lw calc L

G=

Back calculation with XL usi


Where Adiv = 10log(2π Aatm = (αf.r) /10

r is the distancαf is the atmos


Lp measurements are - hard ground (- with barrier ef

Contours are calculate- hard ground (- soft ground (G- single band (5- with barrier ef

AT5414/2 Rev 1

X

1 Lp contours (calc)

ng the Hemispherical method (ISO 9613-2)

r2) : Attenuation due to geometrical divergence 00 : attenuation due to atmospheric absorption

e from the source to the receiver, in metres pheric attenuation coefficient, in decibels per kilometre

calculated with CADNA for G = 0) inside plant area and G = 0 or 1 outside the plant area fect and 5 orders of reflection

d with CADNA for G = 0) inside the plant area = 1) outside the plant area 00 Hz) fect and 5 orders of reflection

…

Cont/

Acoustic Technology

Results for a 2D Area Source model with the Hemispherical method


receiver height 4 m Contours distance

Measurement points North South East West

500 North 500 -7.6 -10.9 -8.9 -10.2 500 South 500 -4.2 -7.5 -5.5 -6.8 500 East 500 -6.2 -9.5 -7.5 -8.8 500 West 500 -4 -7.3 -5.3 -6.6 500 North 1000 -7.9 -11.2 -9.2 -10.5 500 South 1000 -13.8 -17.1 -15.1 -16.4 500 East 1000 -10 -13.3 -11.3 -12.6 500 West 1000 -8.8 -12.1 -10.1 -11.4 500 North 2000 -9.4 -12.7 -10.7 -12 500 South 2000 -17.7 -21 -19 -20.3 500 East 2000 -9 -12.3 -10.3 -11.6 500 West 2000 -17.7 -21 -19 -20.3

1000 North 500 -7.6 -6 -7.4 -6.3 1000 South 500 -4.2 -2.6 -4 -2.9 1000 East 500 -6.2 -4.6 -6 -4.9 1000 West 500 -4 -2.4 -3.8 -2.7 1000 North 1000 -7.9 -6.3 -7.7 -6.6 1000 South 1000 -13.8 -12.2 -13.6 -12.5 1000 East 1000 -10 -8.4 -9.8 -8.7 1000 West 1000 -8.8 -7.2 -8.6 -7.5 1000 North 2000 -9.4 -7.8 -9.2 -8.1 1000 South 2000 -17.7 -16.1 -17.5 -16.4 1000 East 2000 -9 -7.4 -8.8 -7.7 1000 West 2000 -17.7 -16.1 -17.5 -16.4 2000 North 500 -7.4 0.5 -7.2 1.6 2000 South 500 -4 3.9 -3.8 5 2000 East 500 -6 1.9 -5.8 3 2000 West 500 -3.8 4.1 -3.6 5.2 2000 North 1000 -7.7 0.2 -7.5 1.3 2000 South 1000 -13.6 -5.7 -13.4 -4.6 2000 East 1000 -9.8 -1.9 -9.6 -0.8 2000 West 1000 -8.6 -0.7 -8.4 0.4 2000 North 2000 -9.2 -1.3 -9 -0.2 2000 South 2000 -17.5 -9.6 -17.3 -8.5 2000 East 2000 -8.8 -0.9 -8.6 0.2 2000 West 2000 -17.5 -9.6 -17.3 -8.5


SUMMARY SHEET 16.4: Open Industrial Site Modelled as a 2D Area Source Using Stüber


Industrial Site 2D Area source Measurement around the plant area at 4 m height Contours at 500 m, 1000 m, 2000 m Method used for the calculations

XL

Lp contours (true)

Lp meas (true)

Lw true

G=0, Receivers around the plant area

G=1

G=1 Lw calc Lp contours

(calc)

Back calculation with XL using the Stüber method using the standard BS ISO 8297 : 1994





Lp measurement are calculated with CADNA for hard ground (G = 0) inside Sm and G = 0 or 1 outside the plant area (Sm) with barrier effect and 5 orders of reflection


hard ground (G = 0) inside the plant area (Sm) soft ground (G = 1) outside the plant area (Sm) a single band (500 Hz) with barrier effect and 5 orders of reflection

…

AT5414/2 Rev 1 Ac

Cont/

oustic Technology

Dimensions: L (m) 230 Largest Dimension of Plant area Sm (m2) 29227 Measurement Area l (m) 700 Length of the measurement contour Sp (m2) 23149 Plant Area d (m) 10 Average measurement distance Dm (m) 17.50 Distance between measurement position (Dm<2d) d “condition” 7.6 < d < 35

Results for a 2D Area Source model using the Stuber method for a single band 500 Hz

Real site with contour line,

G=1 outside the measurement area Source and Receivers at 4 m

Real site with contour line, G=0 outside the measurement area

Source and Receivers at 4 m


receiver height 4 m


receiver height 4 m Contours distance North South East West

Contours distance North South East West

500 4.0 1.0 2.8 1.6 500 4.8 1.8 3.6 2.4 1000 4.2 6.1 4.4 5.5 1000 5.0 6.9 5.2 6.3 2000 4.0 7.9 2.9 11.3 2000 4.8 8.7 3.7 12.1

Flat area,



Source and Receivers at 4m


receiver height 4 m


receiver height 4 m Contours distance North South East West

Contours distance North South East West

500 4.1 4.6 2.4 2.5 500 4.9 5.4 3.2 3.3 1000 4.8 8.1 3.9 3.6 1000 5.6 8.9 4.7 4.4 2000 5.9 10.6 3.8 11.8 2000 6.7 11.4 4.6 12.6


SUMMARY SHEET 16.5: Open Industrial Site Modelled as a Point Source Using


Industrial Site Point source Measurement at 4 m height and at 300 m from site centre Contours at 500 m, 1000 m, 2000 m Method used for the calculations

XL Lp contours (calc)

Lw calc

Lp contours (true)

Lp meas (true)

Lw true

G=0 or G=1 at 300m

G=1

G=1

Back calculation with XL using the Hemispherical method (ISO 9613-2)


Where Adiv = 10log(2πr2) : Attenuation due to geometrical divergence Aatm = (αf.r) /1000 : attenuation due to atmospheric absorption



Lp measurements are calculated with CADNA for - hard ground (G = 0) inside plant area and G = 0 or 1 outside the plant area - with barrier effect and 5 orders of reflection

Contours are calculated with CADNA for - hard ground (G = 0) inside the plant area - soft ground (G = 1) outside the plant area - single band (500 Hz) - with barrier effect and 5 orders of reflection -

…

AT5414/2 Rev 1 Ac

Cont/

oustic Technology

Results for a Point Source model with the Hemispherical method



Error LpA Calc - LpA True Error LpA Calc - LpA True



Contours distance,

m Measurement


Contours distance,

m Measurement

points North South East West500 North 300m -3.4 -7.5 -5.3 -7.4 500 North 300m -0.2 -4.3 -2.1 -4.2500 South 300m -0.3 -4.4 -2.2 -4.3 500 South 300m 2.6 -1.5 0.7 -1.4500 East 300m 2.1 -2 0.2 -1.9 500 East 300m 4.8 0.7 2.9 0.8500 West 300m -3 -7.1 -4.9 -7 500 West 300m -0.3 -4.4 -2.2 -4.31000 North 300m -4.3 -3.6 -5.2 -8.1 1000 North 300m -1.1 -0.4 -2 -4.91000 South 300m -1.2 -0.5 -2.1 -5 1000 South 300m 1.7 2.4 0.8 -2.11000 East 300m 1.2 1.9 0.3 -2.6 1000 East 300m 3.9 4.6 3 0.11000 West 300m -3.9 -3.2 -4.8 -7.7 1000 West 300m -1.2 -0.5 -2.1 -5 2000 North 300m -4.5 0.1 -5.4 2.8 2000 North 300m -1.3 3.3 -2.2 6 2000 South 300m -1.4 3.2 -2.3 5.9 2000 South 300m 1.5 6.1 0.6 8.82000 East 300m 1 5.6 0.1 8.3 2000 East 300m 3.7 8.3 2.8 11 2000 West 300m -4.1 0.5 -5 3.2 2000 West 300m -1.4 3.2 -2.3 5.9

Flat area, G=1 outside the measurement area Flat area, G=0 outside the measurement area

Error LpA Calc - LpA True Error LpA Calc - LpA True at distances from acoustic

centre, m, receiver height 4 m at distances from acoustic

centre, m, receiver height 4 mContours distance,

m Measurement


Contours distance,

m Measurement

points North South East West500 North 300m -1.9 -1.4 -3.5 -3.5 500 North 300m 1.4 1.9 -0.2 -0.2500 South 300m -1.6 -1.1 -3.2 -3.2 500 South 300m 1.4 1.9 -0.2 -0.2500 East 300m 1.6 2.1 0 0 500 East 300m 4.5 5 2.9 2.9500 West 300m 0.1 0.6 -1.5 -1.5 500 West 300m 2.7 3.2 1.1 1.1

1000 North 300m -1.2 2.1 -2 -2.4 1000 North 300m 2.1 5.4 1.3 0.91000 South 300m -0.9 2.4 -1.7 -2.1 1000 South 300m 2.1 5.4 1.3 0.91000 East 300m 2.3 5.6 1.5 1.1 1000 East 300m 5.2 8.5 4.4 4 1000 West 300m 0.8 4.1 0 -0.4 1000 West 300m 3.4 6.7 2.6 2.22000 North 300m -0.1 4.7 -2.1 6.3 2000 North 300m 3.2 8 1.2 9.62000 South 300m 0.2 5 -1.8 6.6 2000 South 300m 3.2 8 1.2 9.62000 East 300m 3.4 8.2 1.4 9.8 2000 East 300m 6.3 11.1 4.3 12.72000 West 300m 1.9 6.7 -0.1 8.3 2000 West 300m 4.5 9.3 2.5 10.9


SUMMARY SHEET 16.6: Open Industrial Site Modelled as a Point Source Using


Industrial Site Point source Measurement at 4 m height and at 500 m, 1000 m, 2000 m from site centre Contours at 500 m, 1000 m Method used for the calculations

G=1 Lp contours (true)

Lp meas (true)

Lw true

G=0 or G=1 at 500, 1000, 2000m

Lw calc L

G

Back calculation with XL us


Where Adiv = 10log(2 Aatm = (αf.r) /1

r is the distanαf is the atmo


Lp measurements are- hard ground - with barrier e

Contours are calcula- hard ground - soft ground (- single band (- with barrier e-

AT5414/2 Rev 1

X

=1 Lp contours (calc)

ing the Hemispherical method (ISO 9613-2)

πr2) : Attenuation due to geometrical divergence 000 : attenuation due to atmospheric absorption

ce from the source to the receiver, in metres spheric attenuation coefficient, in decibels per kilometre

calculated with CADNA for (G = 0) inside plant area and G = 0 or 1 outside the plant area ffect and 5 orders of reflection

ted with CADNA for (G = 0) inside the plant area G = 1) outside the plant area 500 Hz) ffect and 5 orders of reflection

…

Cont/
Acoustic Technology

Results for a Point Source model with the Hemispherical method

Error LpA Calc - LpA True at distances from acoustic

centre, m, receiver height 4 m Contours distance

Measurement points North South East West

500 North 500 -5.7 -10.9 -8.7 -10.6 500 South 500 -2.3 -7.5 -5.3 -7.2 500 East 500 -4.3 -9.5 -7.3 -9.2 500 West 500 -2.1 -7.3 -5.1 -7 500 North 1000 -6 -11.2 -9 -10.9 500 South 1000 -11.9 -17.1 -14.9 -16.8 500 East 1000 -8.1 -13.3 -11.1 -13 500 West 1000 -6.9 -12.1 -9.9 -11.8 500 North 2000 -7.5 -12.7 -10.5 -12.4 500 South 2000 -15.8 -21 -18.8 -20.7 500 East 2000 -7.1 -12.3 -10.1 -12 500 West 2000 -15.8 -21 -18.8 -20.7

1000 North 500 -7.6 -5.9 -7.1 -6.3 1000 South 500 -4.2 -2.5 -3.7 -2.9 1000 East 500 -6.2 -4.5 -5.7 -4.9 1000 West 500 -4 -2.3 -3.5 -2.7 1000 North 1000 -7.9 -6.2 -7.4 -6.6 1000 South 1000 -13.8 -12.1 -13.3 -12.5 1000 East 1000 -10 -8.3 -9.5 -8.7 1000 West 1000 -8.8 -7.1 -8.3 -7.5 1000 North 2000 -9.4 -7.7 -8.9 -8.1 1000 South 2000 -17.7 -16 -17.2 -16.4 1000 East 2000 -9 -7.3 -8.5 -7.7 1000 West 2000 -17.7 -16 -17.2 -16.4

…

AT5414/2 Rev 1

Cont/

Acoustic Technology

SUMMARY SHEET 16.7: Open Industrial Site Modelled as a Point Source Using Stüber


Industrial Site Point source Measurement around the plant area at 4 m height Contours at 500 m, 1000 m, 2000 m Method used for the calculations

G=0 or G=1, Receivers around the plant area

Lp contours (true)

Lp meas (true)

Lw calc L

Lw true G=1

G=

Back calculation with XL usi

Lw = Lpaverage + ∆Ls + ∆ Where ∆Ls = 10log((2

∆Lα = 0.5*α√S ∆Lf = log (d/(4

Sm is the meah is the micropl is the length α is the soundd is the Measu


Lp measurement are c hard ground ( with barrier ef

Contours are calculate

hard ground ( soft ground (G a single band with barrier ef

AT5414/2 Rev 1

X

1 Lp contours (calc)

ng the Stüber method using the standard BS ISO 8297 : 1994

Lα + ∆Lf

Sm+h.l)/S0) : area term m : atmospheric absorption √ Sp) : proximity correction

surement area in squares metres hone height, in metres

of the measurement contour, metres attenuation coefficient through air, in decibels per metre rement distance, in metres

alculated with CADNA for G = 0) inside Sm and G = 0 or 1 outside the plant area (Sm) fect and 5 orders of reflection

d with CADNA for G = 0) inside the plant area (Sm) = 1) outside the plant area (Sm) (500 Hz) fect and 5 orders of reflection

Acoustic Technology


Dimensions: L (m) 230 Largest Dimension of Plant area Sm (m2) 29227 Measurement Area l (m) 700 Length of the measurement contour Sp (m2) 23149 Plant Area d (m) 10 Average measurement distance Dm (m) 17.50 Distance between measurement position (Dm<2d) d “condition” 7.6 < d < 35 Results for a Point Source model using the Stüber method for a single band 500 Hz


Source and Receivers at 4 m




centre, m, receiver height 4 m

Error LpA Calc - LpA True at distances from acoustic centre,

m, receiver height 4 m Contours distance, m North South East West

Contours distance, m North South East West

500 5.1 1.0 3.2 1.1 500 5.9 1.8 4.0 1.9 1000 4.2 4.9 3.3 0.4 1000 5.0 5.7 4.1 1.2 2000 4.0 8.6 3.1 11.3 2000 4.8 9.4 3.9 12.1

Flat area,





centre, m, receiver height 4 m

Error LpA Calc - LpA True at distances from acoustic centre,

m, receiver height 4 m Contours distance, m North South East West

Contours distance, m North South East West

500 4.1 4.6 2.5 2.5 500 4.9 5.4 3.3 3.3 1000 4.8 8.1 4.0 3.6 1000 5.6 8.9 4.8 4.4 2000 5.9 10.7 3.9 12.3 2000 6.7 11.5 4.7 13.1

research contract: noise mapping industrial sources

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