metrological control of global navigation satellite … · metrological control of global...

Metrological Control of Global Navigation Satellite System (GNSS) Equipment

Laboratorio de Control Metrológico deInstrumental Geodésico y Topográfico

Metrological Control Laboratory of Geodetic and Topographic Instruments

Satellite System (GNSS) EquipmentTeresa Fernández Pareja

Miguel C. Cortés Calvo

1st Workshop Metrology for Long Distance Surveying

Caparica, 21 novembro 2014


1. INTRODUCTION

2. EXPERIMENTAL STAGE

3. LOCAL CALIBRATION CORRECTIONS

Agenda

Metrological Control of GNSS Equipment 1


4. CONCLUSIONS


1. INTRODUCTION



Agenda



4. CONCLUSIONS


1. Introduction

- Why the metrological control and the determination ofthe quality of measurement with GNSS equipment isneeded.

- Need of periodically verification and calibration of those

Metrological Control of GNSS Equipment

- Need of periodically verification and calibration of thoseequipment.

- How to perform calibrations in accredited labs with animplemented quality management system.

- Contribution to the design of the Technical CalibrationProcedures (TCPs) adapted to geodetic instruments

• Studies and Researches

3


1. Introduction








4


1. Introduction








5


1. Introduction








cont.

6


- Regarding GNSS equipment, consensus does not existand the traceability of measurements and theiruncertainties are not assured.

- To ensure the traceability in GNSS equipment calibration,

1. Introduction


- To ensure the traceability in GNSS equipment calibration,through several solutions using different controlnetworks.

7


- Regarding GNSS equipment, consensus does not existand the traceability of measurements and theiruncertainties are not assured.

- To ensure the traceability in GNSS equipment calibration,

1. Introduction


- To ensure the traceability in GNSS equipment calibration,through several solutions using different controlnetworks.

8


Agenda

1. INTRODUCTION


- CONTROL NETWORKS CONSIDERED IN THIS RESEARCH


- CONTROL NETWORKS CONSIDERED IN THIS RESEARCH

- TCPs. DESIGN & DEVELOPMENT

- METROLOGICAL TRACEABILITY OF EXPERIMENTAL

NETWORKS AND UNCERTAINTY ESTIMATION


4. CONCLUSIONS

9


RGECRed Geodésica

Experimental de

Cercedilla

CORRALESVENTORRILLO

JULIÁN DE BLAS


JUAN MORALES

REAJO ALTO

MIRADOR

10


RGEC


REAJO ALTO JULIÁN DE BLAS

11


RGEC

• Great stability

• Suitable geometric distribution

• Good access, distances, locations,


• Good access, distances, locations, etc.

ACCEPTED

12


• Suitable design for calibration of EDM equipment calibration

• Suitable design for calibration of angular measurement equipment

BLMBase Lineal

Multipunto


ACCEPTED


10 m 20 m 30 m 40 m 50 m 60 m0

13,4 m 38,5 m 60 m0 m

D1= 13,4 m

D2= 38,5 m

BLM


Pillar A Pillar B Pillar C Pillar D

D3= 60,0 m

D1= 25,1 m

D5= 46,6 m

D6= 21,5 m


14

• Geometrically ideal triangle

• Adapted for all kinds of observations

• Difficulty of access

ATAZAR

550 m


15

9

• Difficulty of access

ACCEPTED

15

550 m

730 m

720 m


RGECBCA

Cercedilla

Location of standard networks

Base de ValladolidRejected


AtazarDam

BLMMadrid

DehesaMadrid

Rejected

16


- TECHNICAL CALIBRATION PROCEDURES (TCPs). DESIGN & DEVELOPMENT

- Calibration process, data treatment, uncertainty estimation,results interpretation:

- More suitable and that adjusts to the requirements of design

2. Experimental stage


- The TCP structure is the one used by CEM (SpanishMetrological Centre) in its procedures

17


- TECHNICAL CALIBRATION PROCEDURES. DESIGN & DEVELOPMENT

- Geodetic equipment Technical Calibration Procedures

- Design and development of technical calibration procedure forTheodolitesTheodolites

- Design and development of technical calibration procedure for LevelsLevels



- Design and development of technical calibration procedure for LevelsLevels

- Design and development of technical calibration procedure for ElectroElectro--optical Distance Meters (EDM) instrumentsoptical Distance Meters (EDM) instruments

- Design and development of technical calibration procedure formeasuring the frequencyfrequency ofof thethe EDMEDM instrumentsinstruments

- Design and development of technical calibration procedure for GNSSGNSSEquipmentEquipment (Global Navigation Satellite System)

- TLS equipment tests

18


GNSS Equipment TCPRover 2

Base

Rover 1



Design and development of TCP for GNSS equipment

• Uncertainty balance

Magnitude Xi

Estimated value

xi

Standard uncertainty

u(xi)

Probability distribution

Sensitivity coefficient

ci

Contribution to the uncertainty

ui(y)

Antenna centre

cc

12)( c

c

ecu =

rectangular 1

12)( c

c

ecu =

Repeatability of the process

of measurement xM yM hM

sx

sy

sh

xx ssu =)(

yy ssu =)(

hh ssu =)(

normal 1

28)(

2∑

=x

x

r

su

28)(

2∑

=y

y

r

su

28)(

2∑

=h

h

r

su

Repeatability of the process

of measurement

xyM

sxy xyxy ssu =)( normal 1 28

)(

22∑ ∑+

=yx

xy

rr

su

True

xv

yv Combined standard

)()()()( 222xxcV sucucuxu ++=

)()()()( 222 sucucuyu ++=


Antenna height

ci

3

2)( i

mmcu =

rectangular 1 3

2)( i

mmcu =

Geoid model

cg u(cg) u(cg)

Base stations position

cx

cy u(cx) u(cy)

u(cx) u(cy)

Base stations height

ch u(ch) u(ch)

True coordinates

yv

hv Combined standard

uncertainty )()()()( 222

yycV sucucuyu ++=

)()()()()( 2222hhgiV sucucucuhu +++=

Effective degrees of freedom νeff

28

)(

)((y)4

4

1=i i

4

4

ffxx

V

Ni

e su

xu

u

u ==

∑ ν

ν

28

)(

)((y)4

4

1=i i

4

4

ffyy

V

Ni

e su

yu

u

u ==

∑ ν

ν

28

)(

)((y)4

4

1=i i

4

4

ffhh

V

Ni

e su

hu

u

u ==

∑ ν

ν

Coverage factor k )( ffefk ν=

Expanded uncertainty U

)( VxukU ⋅=

)( VyukU ⋅=

)( VhukU ⋅=

20


- REPEATABILITY EVALUATION OF GNSS EQUIPMENT

- Leica 1200+, Trimble R8 and Trimble GeoXH

- BCA (Base de Control Altimétrico) in Cercedilla

- BLM



- BLM

- Analysis of results


REPEATABILITY EVALUATION of GNSS EQUIPMENT in BCA

Bar diagram with the experimental standard deviations of the three GNSS models, calculated for a given position, sISO-GNSSxy, and ellipsoidal height,sISO-GNSSh



REPEATABILITY EVALUATION of GNSS EQUIPMENT in BLM

Bar diagram with the experimental standard deviations of the three GNSS models, calculated for a given position, sISO-GNSSxy, and ellipsoidal height,sISO-GNSSh



REPEATABILITY EVALUATION of GNSS EQUIPMENT in BCA and BLM

- Two clearly different groups of results

- No significant differences to reject any of those equipments

- Proposal: To determine periodically sISO-GNSSxy and sISO-GNSSh of GNSS equipment in BCA and BLM in order to have a historical record file that allows to infer a


in BCA and BLM in order to have a historical record file that allows to infer a solid conclusion



- METROLOGICAL TRACEABILITY OF EXPERIMENTAL NETWORKS AND UNCERTAINTY ESTIMATION

- Measurement model and uncertainty contributions


- Metrological traceability in RGEC, BLM and El Atazarnetwork



- METROLOGICAL TRACEABILITY OF EXPERIMENTAL NETWORKS AND UNCERTAINTY ESTIMATION

- Measurement model and uncertainty contributions


This is the starting point in the GNSS equipment calibration using standard networks

- Metrological traceability in RGEC, BLM and Atazarnetwork

Observation and processing


RGEC observations. Measurements and process

sxy and sh of the bases obtained with Leica 1200+ and Trimble R8

0,0043

0,00530,0051

0,0043

0,0038

0,0045

0,003

0,004

0,005

0,006

sxy (m)

0,0042

0,0051 0,0050

0,00420,0039

0,0044

0,003

0,004

0,005

0,006

sh (m)


0,0011 0,0013 0,0013 0,0013 0,00130,0017

0,0038

0,000

0,001

0,002

0,003

LEICA 1200+

TRIMBLE R8

sxy and sh Leica 1200+ < sxy and sh Trimble R8, being practically constant differences in allthe bases for sh and sxy

27

0,00220,0023 0,0025

0,00210,0019

0,0028

0,0039

0,000

0,001

0,002

0,003


0,0097 0,0093 0,0093

0,006

0,008

0,010

0,012

sxy (m)

LEICA 1200+0,0073 0,0074

0,01010,0093

0,0098

0,006

0,008

0,01

0,012

sh (m)

Atazar Network observations. Measurements and process

sxy and sh of the bases obtained with Leica 1200+ and Trimble R8


0,0038 0,00440,0036

0,000

0,002

0,004

0,006

9 15 14

LEICA 1200+

TRIMBLE R80,0056

0

0,002

0,004

0,006

9 15 14

sh are slightly bigger than the calculated ones for a position, sxy, with both models of equipments.

sxy and sh Leica 1200+ < sxy and sh Trimble R8. The differences are not significant enough to choose anyof both equipments, so that anyone of them would be acceptable for point positioning within ageomatic project .

28


• Criteria to determine the contributions to the uncertainty of measure. Estimation of uncertainties

- Metrological model proposed

xv = xm + crepeatability_equip + cc + cion + ctrop + cM + cF + cPDOP + cstatus

yv = ym + crepeatability_equip + cc + cion + ctrop + cM + cF + cPDOP + cstatus

hv = hm + crepeatability_equip + ci + cion + ctrop + cM + cF + cPDOP + cstatus


hv = hm + crepeatability_equip + ci + cion + ctrop + cM + cF + cPDOP + cstatus

29

crepeatability_equip= repeatibility of GNSS equipment

cc = lack of centring correction

ci = antenna height correction

cion = ionosferic correction

ctrop = troposferic correction

cM = multipath correction

cF = lack of coincidence between the radioelectric and mechanical antenna centres correction cPDOP = satellite geometry correction

cstatus = status of both satellite and receiver oscillators correction


Agenda

1. INTRODUCTION





4. CONCLUSIONS


ASSESSMENT OF LOCAL CALIBRATION CORRECTIONS

• Calibration corrections in RGEC

- Local CC in RGEC for the GNSS equipments Leica 1200 + and Trimble R8

0,050

local calibration corrections [m]


-0,020

-0,010

0,000

0,010

0,020

0,030

0,040

0,050

cc Leica 1200+

cc Trimble

31

cc Leica 1200+

cc Trimble R8




- Distances standard uncertainty estimation, ud_axe

- By applying the Law of Propagation of Uncertainty (LPU)

- By applying Monte Carlo Method (MC)


- The results show that the ud_axe estimated by LPU and MC for bothGNSS equipments Leica 1200+ and Trimble R8 do not differsignificantly

32




Expanded uncertainty of local calibration corrections, Uc-axe

Uc-eae Axes Leica 1200+[m]

Trimble R8[m]

Uc-1-2 Julián de Blas - Juan Morales ±0,022 ±0,028

Uc-1-3 Julián de Blas – Reajo Alto ±0,022 ±0,029


c-1-3 0,022 0,029

Uc-1-4 Julián de Blas - Corrales ±0,021 ±0,027

Uc-1-5 Julián de Blas - Ventorrillo ±0,022 ±0,026

Uc-1-6 Julián de Blas - Mirador ±0,025 ±0,031

Uc-2-3 Juan Morales - Reajo Alto ±0,020 ±0,025

Uc-2-4 Juan Morales - Corrales ±0,022 ±0,026

Uc-2-5 Juan Morales - Ventorrillo ±0,024 ±0,028

Uc-2-6 Juan Morales- Mirador ±0,022 ±0,027

Uc-3-4 Reajo Alto - Corrales ±0,020 ±0,025

Uc-3-5 Reajo Alto - Ventorrillo ±0,022 ±0,026

Uc-3-6 Reajo Alto - Mirador ±0,021 ±0,027

Uc-4-5 Corrales - Ventorrillo ±0,021 ±0,025

Uc-4-6 Corrales - Mirador ±0,021 ±0,027

Uc-5-6 Ventorrillo - Mirador ±0,023 ±0,028

33



• Calibration corrections in BLM

Standard uncertainty of local calibration corrections and its expanded uncertainty, for both GNSS equipments Leica 1200 + and Trimble R8


uc Uc (k=2)

Leica 1200+ 0,008 m ±0,016 m

Trimble R8 0,010 m ±0,020 m


Agenda

1. INTRODUCTION





4. CONCLUSIONS


- Suitability of the control networks for verification and/or calibration of GNSS equipment

- Technical Calibration Procedures (TCP)

4. Conclusions


• Norm ISO/IEC 17025:2005• Laboratory / Field

- Traceability of control networks

• Traceability RGEC, BLM, El Atazar• Increase of observation periods

36


- Suitability of the control networks for verification and/or calibration of GNSS equipments


4. Conclusions




• Traceability RGEC, BLM, El Atazar• Increase of observation periods

37


- Suitability of the control networks for verification and/or calibration of GNSS equipments


4. Conclusions




• Infrastructure, resources, personal• Increase of observation periods

cont.

38


- Estimation of uncertainty in measurement of GNSS equipment

• Estimated uncertainties comply with provider specifications. • Detected a lack of standardization• No significant differences between high accuracy equipment

4. Conclusions


• No significant differences between high accuracy equipment

- Calibration corrections and estimation of uncertainty

• BLM: Need to be observed again• Propagation of uncertainty vs Monte Carlo

39


- Estimation of uncertainty in measurement of GNSS equipment

• Estimated uncertainties comply with provider specifications. • Detected a lack of standardization• No significant differences between high accuracy equipment

4. Conclusions


• No significant differences between high accuracy equipment

- Calibration corrections and estimation of uncertainty

• BLM: Need to be observed again

cont.

40


4. Conclusions

- Appropriate Metrological Control for equipment

• high quality measurement equipment vs period of use is reduced• calibration/verification of each of the parts forming the GNSS system• proposal is not complex: robust, efficient and easy to implement


TO CALIBRATE THE EQUIPMENT AS IT IS USED


Thank you for

paying attention



Teresa F. Pareja

[email protected]

paying attention

Metrological Control of Global Navigation Satellite System (GNSS) Equipment



Satellite System (GNSS) EquipmentTeresa Fernández Pareja

Miguel C. Cortés Calvo

1st Workshop Metrology for Long Distance Surveying

Caparica, 21 novembro 2014

metrological control of global navigation satellite … · metrological control of global...

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