data specification elevation v3 - inspire · • common set of rules assuring aggregation of grid...

1

INSPIRE DS Highlights

Data Specification Elevation v3.0

Jordi Escriu - TWG EL EditorInstitut Cartogràfic de Catalunya (ICC)

INSPIRE Conference 2012

Istanbul, 25th - 27th June 2012

2

This presentation

� TWG Elevation

� INSPIRE Data Specification Elevation v3.0

� EL Theme overview

� Scope

� DS Key aspects

� Model structure

� Results (Application schemas)

INSPIRE DS Highlights – Data Specification Elevation v3.0 2

3Nov’ 10 – DS EL v1

delivery

TWG ElevationMichael Hovenbitzer (Facilitator)

Jordi Escriu Paradell (Editor)

Chris Howlett

Dave Capstick

Eduardo González

Gyula Iván

Lee Brinton

Lynne Allan

Rogier Broekman

Tim Kearns

Veijo Pätynen

Vincent Donato

Zdzislaw Kurczyński

Katalin Tóth (EC- JRC contact point)

3

I II III IV

20122010 2011

II III IV I II III

May’ 10

Kick-off Frankfurt

Jun’ 11 – DS EL v2

delivery

Nov’ 10

Warsaw

Mar’ 11

Barcelona

Apr’ 12 – DS EL v3

delivery

Nov’ 11

Budapest

Feb’ 12

Ispra

4

Elevation theme

• Definition

“Digital elevation models for land, ice and ocean surface. Includes

terrestrial elevation, bathymetry and shoreline.”

[INSPIRE Directive, 2007/2/EC]

• Description

“The theme includes:

Terrestrial elevation (namely land-elevation), represented as:

– Digital Terrain Models (DTM) describing the three-dimensional shape

of the Earth’s surface (ground surface topography).

– Digital Surface Models (DSM) specifying the three dimensional

geometry of every feature on the ground, for example vegetation,

buildings and bridges.

Bathymetry data, e.g. a gridded sea floor model”

[Adapted from INSPIRE Feature Concept Dictionary]


5

Elevation theme

• Relationships with other INSPIRE themes

– Geographical names – Summits, mountain passes, singular spots

– Hydrography / Administrative Units – Data consistency

– Sea Regions – Shoreline (Coastline)

– Buildings / Utility and governmental services / others3

• Attributes storing absolute elevations

• Identification of the Vertical CRS to which these are referenced

– Orthoimagery (& others using grids)

• Modelling of Grids as coverages

– Elevation present in use cases of many themes as input data


6

Reference materials

Reference documents

• 36 received and analysed

User requirements survey

• 44 received

• 4 Key use cases selected

– Flooding

– Orthoimagery production

– Maintenance of fairways

– Elevation mapping


7

DS Scope


Modelling of surfaces

• 2.5-D model, only one value per

horizontal position

• Digital Terrain Model (DTM) orG

• Digital Surface Model (DSM)

• Measurement procedures

• Shoreline

INSPIRE Data Specifications

on Sea Regions, ‘CoastLine’

Feature type

Data representations

• Vector data (2-D or 2.5-D)

• Grid data (coverages)

• TIN data

In the scope

Out of the scope

Content

• Absolute gravity-related elevation

properties (heights and depths), forG

• Land elevation

• Bathymetry of the Sea, inland water

bodies and navigable river courses

8

DS Key aspects (I)

• Homogenous / Integrated approach to

– Representation of different surfaces:

• DTM

• DSM

– Land elevation and bathymetry data (integrated land-sea models)

– Different spatial representation types:

• Grid

• Vector

• TIN

• Identifier management

– Unique identifiers mandated only for Grids and TIN objects

• Temporal representation: life-cycle information

– beginLifespanVersion / endLifespanVersion (voidable)


9

Digital elevation models (DEM):

difference between DTM and DSM

9

Land-elevation sub-theme Bathymetry sub-theme

Dynamic features

Varying water level

Dynamic features

Varying water level

Digital Terrain Model (DTM)

Digital Surface Model (DSM)

Bare terrain surface

10

Graphical examples:

Measuring of elevation properties


Positive Height

(Negative Depth)

Earth’s surface

Varying water level

Vertical reference

level – Datum

Land

Spot –elevation

Bathymetry

Spot –elevation


Positive Depth

(Negative Height)

11

Example: Description of an integrated

land-sea model

11

Positive Height

Earth’s surface

Varying water level

Vertical reference

level – Datum

Land

Spot –elevation

Bathymetry

Spot –elevation


Negative Height

NOTES

1. This example shows how an integrated land-sea model may be expressed e.g. as heights referenced to a single vertical

CRS. Alternatively, it may be expressed as depths (this alternative is not the one shown in the figure).

INSPIRE DS Highlights – Data Specification Elevation v3.0

12

DS Key aspects (II)

• Coordinate Reference Systems

– Land elevation


Geographical Scope CRS to be used

Inside ETRS89 scope

(continental Europe)

ETRS89-GRS80 recommended

Heights: EVRS mandated (IR Data Interoperability)

Outside ETRS89 scope

(overseas territories)

MS to decide and identify

Heights: Earth Gravitational Model (EGM Version 2008) recommended

13

Example: Description of land-

elevation

13

Positive Height

Land surface

Varying water level

Vertical reference

level – Datum

Land

Spot –elevation

Land-elevation sub-theme


14

DS Key aspects (III)

• Coordinate Reference Systems

– Bathymetry


Geographical Scope Vertical reference to be used

Sea - Tidal Waters

Lowest Astronomical Tide (LAT) *

(*) In in open oceans and effectively in waters that are deeper than 200

meters LAT may be approximated by MSL due to overall inaccuracy of

depths measurements): MSL to be used.

Sea - Non-tidal Waters Mean Sea Level (MSL)

Inland standing

water bodies

Local reference level *

(*) The height of this reference shall be provided and referenced to a

gravity-related reference system

- EVRS, within its geographical scope

- Reference system identified by MS, outside this scope

Navigable riversCollection of local reference levels, along the river section *

(*) The same previous note, for each reference level used.

15

Example: Description of the sea floor

15

Sea floor

Varying water level

Vertical reference level – Datum

Bathymetry

Spot –elevation

Bathymetry sub-theme

Positive DepthReference point A

Reference point B

NOTES

1. In this example the vertical reference level of this sea area is determined using two reference points

(reference point ‘A’ and reference point ‘B’).

2. Both reference points have known elevation offsets from the vertical reference level.


16

Example: Description of the floor of

an inland standing water body

16

Water body floor

Varying water level

Vertical reference level – Datum

Bathymetry

Spot –elevation


Reference point A

NOTES

1. In this example the vertical reference level of the inland standing water body is determined using one reference point

(reference point ‘A’).

2. The reference point have known elevation offset from the vertical reference level (equal to 0 in this example).

Positive Depth


17

Example: Description of the bed of a

navigable river

17

Scope of River section BWhere the vertical reference level is

Datum ‘B’

Scope of River section AWhere the vertical reference level is

Datum ‘A’Reference point B

River bed

Varying water

level

Vertical reference level – Datum A

Bathymetry

Spot –elevation


NOTES

1. In this example two sections ‘A’ and ‘B’ of a river are shown. Each of them has its own vertical reference level (Datum ‘A’ and

Datum ‘B’, respectively).

Positive Depth

Bathymetry

Spot –elevation

Positive Depth

Vertical reference level – Datum B

Reference point A


18

DS Key aspects (IV)

• Geographical Grids:

– Proposal to use a European Common Grid for Raster Data (Grid_ETRS89-

GRS80)

• Hierarchical grid

• Based on ETRS89-GRS80 geodetic coordinates

• DTED structure

• Common set of rules assuring aggregation of grid cells (grid origin, grid cell reference

point)

• Common proposal with other TWG dealing with coverages (e.g. OI)

– Optional use by MS

– Alternative to Grid_ETRS89-LAEA (Lambert Azimuthal Equal Area)

• Aligned with the IR (Section 2.2.2): Other theme-specific grids may be specified

– Main objective:

• Avoid cross-border interoperability problems due to different grid cell alignment rules.


19

Model - Structure


Elevation

Application schemas

INSPIRE Generic

Conceptual Model D2.5

Coverages (Domain and Range)

App. Schema

ISO

Standards

Elevation

Base types

Elevation

Vector Elements

Elevation

Grid Coverage

Elevation

TIN

INSPIRE Elevation

Data Product Specification

D2.8.II.1

INSPIRE Directive

20

Results – Application schemas

20

Describing3

� Common types

[Enumerations]

� Elevation property type

‘height’ / ‘depth’

� Surface type

‘DTM’ / ‘DSM’

[Data type]

� Vertical CRS identifier

‘VerticalCRSIdentifier’

Elevation –Base types

Data type

Enumerations

21


21

Describing3

� Main class

� ‘ElevationGridCoverage’

� Enums. (Base types)

� ‘height’ / ‘depth’

� ‘DTM’ / ‘DSM’

� Conformity to

� Generic Conceptual Model:

Coverages – Domain and range

� ISO 19123:2005:

Coverages geometry and

functions

Elevation –Grid coverage

Elevation Grid

Coverage

Enumerations

22


22

Describing3

� Generic abstract class

� ‘ElevationVectorObject’

� Child features types

� ‘SpotElevation’

� ‘ContourLine’

� ‘BreakLine’, ‘VoidArea’,

‘IsolatedArea’, ‘StopLine’



� Data type

� ‘ChartDatum’ – Solution for use

of non-registered bathymetric

vertical referencesElevation –Vector Elements

Spot Elevation Contour Line

Break Line

Void Area

Isolated

Area

Elevation Vector

Object

Stop Line

Enumerations

Chart Datum

23


23

Elevation -TIN

Elevation TIN

Enumerations

Describing3

� Main class

� ‘ElevationTIN’



� ‘DTM’ / ‘DSM’

� Conformity to

� ISO 19107:2003 – Spatial Schema (‘GM_Tin’)

24INSPIRE DS Highlights – Data Specification Elevation v3.0 24

Thank you for your attention!!

[email protected]

[email protected]

data specification elevation v3 - inspire · • common set of rules assuring aggregation of grid...

Documents