Data Specification Elevation v3.0

INSPIRE DS Highlights Data Specification Elevation v3.0 Jordi Escriu - TWG EL Editor Institut Cartogràfic de Catalunya (ICC) INSPIRE Conference 2012 Istanbul, 25 th - 27 th June 2012 1

This presentation TWG Elevation INSPIRE Data Specification Elevation v3.0 EL Theme overview Scope DS Key aspects Model structure Results (Application schemas) 2 INSPIRE DS Highlights Data Specification Elevation v3.0 2

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 May 10 Kick-off Frankfurt Nov 10 Warsaw Mar 11 Barcelona Nov 11 Budapest Katalin Tóth (EC- JRC contact point) Feb 12 Ispra II III IV I II III IV I II III 2010 2011 2012 Nov 10 DS EL v1 delivery Jun 11 DS EL v2 delivery Apr 12 DS EL v3 delivery 3 3

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 Highlights Data Specification Elevation v3.0 4 4

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 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 5 INSPIRE DS Highlights Data Specification Elevation v3.0 5

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 6 INSPIRE DS Highlights Data Specification Elevation v3.0 6

DS Scope In the scope Content Absolute gravity-related elevation properties (heights and depths), for Land elevation Bathymetry of the Sea, inland water bodies and navigable river courses Modelling of surfaces 2.5-D model, only one value per horizontal position Digital Terrain Model (DTM) or Digital Surface Model (DSM) Data representations Vector data (2-D or 2.5-D) Grid data (coverages) TIN data Out of the scope Measurement procedures Shoreline INSPIRE Data Specifications on Sea Regions, CoastLine Feature type 7 INSPIRE DS Highlights Data Specification Elevation v3.0 7

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) 8 INSPIRE DS Highlights Data Specification Elevation v3.0 8

Digital elevation models (DEM): difference between DTM and DSM Land-elevation sub-theme Bathymetry sub-theme Dynamic features Varying water level Dynamic features Varying water level Bare terrain surface Digital Terrain Model (DTM) Digital Surface Model (DSM) 9 9

Graphical examples: Measuring of elevation properties Land-elevation sub-theme Bathymetry sub-theme Land Spot elevation Vertical reference level Datum Positive Depth (Negative Height) Positive Height (Negative Depth) Varying water level Earth s surface Bathymetry Spot elevation 10 INSPIRE DS Highlights Data Specification Elevation v3.0 10

Example: Description of an integrated land-sea model Land-elevation sub-theme Bathymetry sub-theme Land Spot elevation Vertical reference level Datum Negative Height Positive Height Varying water level Earth s surface Bathymetry Spot elevation 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 11 11

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 12 INSPIRE DS Highlights Data Specification Elevation v3.0 12

Example: Description of landelevation Land-elevation sub-theme Land surface Land Spot elevation Positive Height Varying water level Vertical reference level Datum INSPIRE DS Highlights Data Specification Elevation v3.0 13 13

DS Key aspects (III) Coordinate Reference Systems Bathymetry Geographical Scope Sea - Tidal Waters Sea - Non-tidal Waters Inland standing water bodies Navigable rivers Vertical reference to be used 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. Mean Sea Level (MSL) 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 Collection of local reference levels, along the river section * (*) The same previous note, for each reference level used. 14 INSPIRE DS Highlights Data Specification Elevation v3.0 14

Example: Description of the sea floor Bathymetry sub-theme Varying water level Vertical reference level Datum Reference point A Reference point B Positive Depth Bathymetry Spot elevation Sea floor 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. INSPIRE DS Highlights Data Specification Elevation v3.0 15 15

Example: Description of the floor of an inland standing water body Bathymetry sub-theme Varying water level Positive Depth Vertical reference level Datum Reference point A Water body floor Bathymetry Spot elevation 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). INSPIRE DS Highlights Data Specification Elevation v3.0 16 16

Example: Description of the bed of a navigable river Bathymetry sub-theme Vertical reference level Datum A Vertical reference level Datum B Scope of River section A Where the vertical reference level is Datum A Scope of River section B Where the vertical reference level is Datum B Reference point B Positive Depth Reference point A Bathymetry Spot elevation Positive Depth Varying water level Bathymetry Spot elevation River bed 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). INSPIRE DS Highlights Data Specification Elevation v3.0 17 17

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. 18 INSPIRE DS Highlights Data Specification Elevation v3.0 18

Model - Structure INSPIRE Directive INSPIRE Generic Conceptual Model D2.5 ISO Standards Coverages (Domain and Range) App. Schema Elevation Application schemas Elevation Base types Elevation Vector Elements Elevation Grid Coverage Elevation TIN INSPIRE Elevation Data Product Specification D2.8.II.1 19 INSPIRE DS Highlights Data Specification Elevation v3.0 19

Results Application schemas Elevation Base types Data type Enumerations Describing Common types [Enumerations] Elevation property type height / depth Surface type DTM / DSM [Data type] Vertical CRS identifier VerticalCRSIdentifier 20 20

Results Application schemas Elevation Grid coverage Elevation Grid Coverage Enumerations Describing 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 21 21

Results Application schemas Elevation Vector Elements Void Area Isolated Area Stop Line Spot Elevation Enumerations Elevation Vector Object Contour Line Chart Datum Break Line Describing Generic abstract class ElevationVectorObject Child features types SpotElevation ContourLine BreakLine, VoidArea, IsolatedArea, StopLine Enums. (Base types) height / depth Data type ChartDatum Solution for use of non-registered bathymetric vertical references 22 22

Results Application schemas Elevation - TIN Elevation TIN Enumerations Describing Main class ElevationTIN Enums. (Base types) height / depth DTM / DSM Conformity to ISO 19107:2003 Spatial Schema ( GM_Tin ) 23 23

Thank you for your attention!! jordi.escriu@icc.cat inspire-twg-el@jrc.ec.europa.eu 24 INSPIRE DS Highlights Data Specification Elevation v3.0 24