Data Specification Elevation v2.0

Transcription

1 INSPIRE DS Stream Data Specification Elevation v2.0 Jordi Escriu Paradell - TWG EL Editor Institut Cartogràfic de Catalunya (ICC) INSPIRE Conference 2011 Edinburgh, 29 th June -1 st July

2 This presentation TWG Elevation INSPIRE Data Specification Elevation (v2.0) Overview Elevation theme Reference materials Scope Results and achievements Key aspects UML Model Open issues 2 INSPIRE DS Stream Data Specification Elevation v2.0 2

3 TWG Elevation May 2010 TWG EL Nov Kick-off 2010 End Nov TWG 2010 March EL 2011 TWG June EL 2011 Meeting Frankfurt Meeting Delivery Warsaw of DS Meeting EL v1 Barcelona Delivery of DS EL v2 Michael 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) April 2012 Delivery of DS EL v3 II III IV I II III IV I II III 3 INSPIRE 2010 DS Stream Data Specification Elevation 2011 v

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] INSPIRE DS Stream Data Specification Elevation v

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 / others Properties storing absolute elevations Identification of the Vertical CRS to which these are referenced Orthoimagery (& others using grids) Modelling of Grids as coverages Use cases of many themes use Elevation data as input for spatial analyses (EL present in 11 use cases) 5 INSPIRE DS Stream Data Specification Elevation v2.0 5

6 Reference materials Reference documents 36 received and analysed User requirements survey 44 received 4 Key use cases selected Flooding Orthoimagery production Safety in maritime and hydrographic navigation Elevation mapping 6 INSPIRE DS Stream Data Specification Elevation v2.0 6

7 DS Scope Content In the scope Land elevations: Absolute gravity-related heights Bathymetry Sea and inland water bodies depths Modelling of surfaces 2.5-D, only one value per planimetric position Either a Digital Terrain Model (DTM) or a Digital Surface Model (DSM) Out of the scope Measurement procedures from which elevation properties are gathered Bathymetry of river courses Coastline INSPIRE Data Specifications on Sea Regions, CoastLine Feature type Data representations Vector data (2-D and 3-D geometries) Gridded data (coverages) TIN data 7 INSPIRE DS Stream Data Specification Elevation v2.0 7

8 Key aspects (I) Homogenous / Integrated approach to Land elevation and bathymetry data (elevation properties) Representation of different surfaces: DTM, DSM Different spatial representation forms: Vector, Grid, TIN Identifier management Unique identifiers mandated for vector spatial objects, grid coverages and TIN structures Object life-cycle information (voidable) beginlifespanversion / endlifespanversion Coordinate Reference Systems (requirements / recommendations) Geographical Scope CRS to be used Inside ETRS89 scope (continental Europe) Outside ETRS89 scope (overseas territories) ETRS89-GRS80 recommended Heights: EVRS mandated (IR Data Interoperability) MS to decide and identify Heights: Earth Gravitational Model (EGM Version 2008) recommended Identification of the Vertical CRS is needed! - Mechanism provided in the EL model 8 INSPIRE DS Stream Data Specification Elevation v2.0 8

9 Key aspects (II) Cross-border interoperability (Grids): Main Issues: MS Data is stored using national grids (different CRSs and map projections) This makes necessary to perform transformations with their inherent quality lose. National grids uses different grid cell alignment rules. Possible solution to fix these issues Provide Elevation data using a Common European / Global Grid. Existing common grid Grid_ETRS89-LAEA, established as the multipurpose Pan-European standard by the IR on Data Interoperability (Annex I - DS on Geographical Grid Systems). Based on the ETRS89 Lambert Azimuthal Equal Area CRS (ETRS89-LAEA) Main purpose: Framework for spatial analysis and reporting Not appropriate for Elevation data PROPOSAL: European Common Grid for Raster Data (Grid_ETRS89-GRS80) Hierarchical grid based on ETRS89-GRS80 geodetic coordinates Common set of rules assuring aggregation of grid cells (grid origin, grid cell reference point) Recommended for provision of EL and OI data aimed at cross-border purposes (DS Annex C) Aligned with the IR (Section 2.2.2): Other theme-specific grids may be specified Data based on national grids is totally valid within their geographical scope! 9 INSPIRE DS Stream Data Specification Elevation v2.0 9

10 UML Model - Structure INSPIRE Directive INSPIRE Generic Conceptual Model D2.5 ISO Standards Coverages (Domain and Range) App. Schema Elevation - Base App. Schema Elevation Vector Elements App. Schema Elevation - Coverages App. Schema Elevation - TIN App. Schema INSPIRE Elevation Data Product Specification D2.8.II.1 10 INSPIRE DS Stream Data Specification Elevation v2.0 10

11 UML Model Application schemas Elevation - Base Describing Basic classes ElevationDataSet Generic components Common types [Data types] Vertical CRS identification ElevationCRSReference [Code lists & enumerations] Elevation property type height / depth Surface type DTM / DSM 11 INSPIRE DS Stream Data Specification Elevation v2.0 11

12 UML Model Application schemas Elevation Vector Elements Void Area Isolated Area Spot Height Spot Depth Elevation Vector Object Points Contour Line Break Line Lines Depth Contour Describing Generic abstract class ElevationVectorObject Specialized features types Points SpotHeight, SpotDepth Lines ContourLine, DepthContour Auxiliary objects BreakLine, VoidArea, IsolatedArea' 12 INSPIRE DS Stream Data Specification Elevation v2.0 12

13 UML Model Application schemas Elevation Coverages (Grids) Describing Main class ElevationGridCoverage Elevation property / Surface height / depth DTM / DSM Conformity to Generic Conceptual Model (GCM) ISO 19123:2005 Coverages geometry and functions Current draft of WCS INSPIRE DS Stream Data Specification Elevation v2.0 13

14 UML Model Application schemas Elevation - TIN Describing Main class ElevationTIN Elevation property / Surface height / depth DTM / DSM Conformity to ISO 19107:2003 Spatial Schema Type GM_Tin 14 INSPIRE DS Stream Data Specification Elevation v2.0 14

15 Open issues Bathymetry of river courses Not in the current scope of the DS Needed for relevant use cases like e.g. safety of inland navigation? Cross-theme data consistency Not clear how to achieve positional / logical consistency between data from different INSPIRE themes. Elevation Vector and TIN cross-border data consistency Must be further investigated by the TWG. Grid coverage data aggregation An integrated approach with TWG-OI is needed. Requirements / recommendations on depth measurement Under discussion For the vertical component measuring the depth of the sea floor, where there is an appreciable tidal range, the Lowest Astronomical Tide shall? be used as reference surface. In marine areas without an appreciable tidal range, in open oceans and effectively in waters that are deeper than 200 m, the depth of the sea floor shall? be referenced to the Mean Sea Level. For the vertical component measuring depths above the sea floor in the free ocean, barometric pressure shall be used. Data quality Target results for DQ measures and recommended evaluation procedures. Metadata Mandatory / Optional theme-specific metadata elements - Under discussion. Guidance on specific MD elements e.g. template for Lineage 15 INSPIRE DS Stream Data Specification Elevation v2.0 15

16 Thank you for your attention!! 16 INSPIRE DS Stream Data Specification Elevation v2.0 16