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 2011

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 INSPIRE DS Stream – Data Specification Elevation v2.02

3 End Nov 2010 – Delivery of DS EL v1 TWG Elevation 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) INSPIRE DS Stream – Data Specification Elevation v2.03 IIIIIIIV IIIIIIV I II III May 2010 – TWG EL Kick-off Meeting Frankfurt June 2011 – Delivery of DS EL v2 Nov 2010 – TWG EL Meeting Warsaw March 2011 – TWG EL Meeting Barcelona April 2012 – Delivery of DS EL v3

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 Earths 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 v2.04

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) INSPIRE DS Stream – Data Specification Elevation v2.05

6 Reference materials Refe rence 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 INSPIRE DS Stream – Data Specification Elevation v2.06

7 DS Scope INSPIRE DS Stream – Data Specification Elevation v2.07 In the scope Content 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) Data representations Vector data (2-D and 3-D geometries) Gridded data (coverages) TIN data 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

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) Identification of the Vertical CRS is needed! - Mechanism provided in the EL model INSPIRE DS Stream – Data Specification Elevation v2.08 Geographical ScopeCRS 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

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! INSPIRE DS Stream – Data Specification Elevation v2.09

10 UML Model - Structure INSPIRE DS Stream – Data Specification Elevation v2.010 INSPIRE Generic Conceptual Model D2.5 Coverages (Domain and Range) App. Schema ISO Standards ISO Standards 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 INSPIRE Directive

11 UML Model – Application schemas INSPIRE DS Stream – Data Specification Elevation v2.011 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 Elevation - Base

12 UML Model – Application schemas INSPIRE DS Stream – Data Specification Elevation v2.012 Describing… Generic abstract class ElevationVectorObject Specialized features types Points SpotHeight, SpotDepth Lines ContourLine, DepthContour Auxiliary objects BreakLine, VoidArea, IsolatedArea' Elevation – Vector Elements PointsLines Spot Height Spot Depth Contour Line Depth Contour Break Line Void Area Isolated Area Elevation Vector Object

13 UML Model – Application schemas INSPIRE DS Stream – Data Specification Elevation v2.013 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 2.0 Elevation – Coverages (Grids)

14 UML Model – Application schemas INSPIRE DS Stream – Data Specification Elevation v2.014 Describing… Main class ElevationTIN Elevation property / Surface height / depth DTM / DSM Conformity to ISO 19107:2003 – Spatial Schema Type GM_Tin Elevation - TIN

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 INSPIRE DS Stream – Data Specification Elevation v2.015 Looking for feedback from the Consultation & Testing Phase!

16 INSPIRE DS Stream – Data Specification Elevation v2.016 Thank you for your attention!!