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[F1ANNEX III U.K. REQUIREMENTS FOR SPATIAL DATA THEMES LISTED IN ANNEX II TO DIRECTIVE 2007/2/EC

Textual Amendments

1. ELEVATION U.K.

1.7. Theme-specific Requirements U.K.

1.7.1. Requirements on external object identifiers U.K.
(1) If elevation data is updated based on new source data, the updated objects shall receive a new external object identifier. U.K.
1.7.2. Requirements for Elevation Grid Coverages U.K.
(1) By way of derogation from the requirement in Section 2.2 of Annex II, any grid compatible with one of the following coordinate reference systems may be used for making gridded Elevation data available: U.K.

The grid specified in Section 2.2.1 of Annex II shall not be used.

(2) The domainExtent attribute of every ElevationGridCoverage instance shall be at least populated with a subtype of the EX_GeographicExtent type. U.K.
(3) The elevation property values included within the range set of a single ElevationGridCoverage shall be referenced to one and only one vertical coordinate reference system. U.K.
(4) All the ElevationGridCoverage instances, to which an aggregated ElevationGridCoverage instance refers, shall be consistent. This means that they shall share the same range type, Coordinate Reference System and resolution. They shall also support grid alignment, i.e. the grid points in one ElevationGridCoverage instance line up with grid points of the other ElevationGridCoverage instances, so that grid cells do not partially overlap. U.K.
(5) The contributing footprints of any two ElevationGridCoverage instances referred to by the same aggregated ElevationGridCoverage instance shall be either adjacent or disjoint. U.K.
(6) The union of the contributing footprints of the ElevationGridCoverage instances referred to by the same aggregated ElevationGridCoverage instance shall determine the geographic extent (domainExtent) of the aggregated ElevationGridCoverage instance. U.K.
(7) The ElevationGridCoverage package shall be restricted to two-dimensional geometries. U.K.
(8) Information about the acquisition dates of data contained in elevation grid coverages shall be provided at least in one of the following ways: U.K.
(a)

by providing the metadata element Temporal reference for each spatial object through the metadata attribute of the spatial object type ElevationGridCoverage;

(b)

by providing the metadata element Temporal reference required by Regulation (EC) No 1205/2008 as a temporal extent.

1.7.3. Requirements for Elevation Vector Data U.K.
(1) Where elevation vector data sets are provided using 2-D geometries, the vertical component (third dimension) shall be provided as elevation property values within the propertyValue attribute. U.K.
(2) Where elevation vector data sets are provided using 2.5-D geometries, the elevation property values shall be only included within the third coordinate (Z) of these geometries. U.K.
1.7.4. Requirements for Elevation TINs U.K.
(1) The property values included within a single instance of ElevationTIN spatial object type (TIN model) shall be referenced to one and only one vertical coordinate reference system. U.K.
(2) Triangles intersecting a stop line shall be removed from a TIN surface, leaving holes in the surface. If coincidence occurs on surface boundary triangles, the result shall be a change of the surface boundary. U.K.
(3) The vector spatial objects provided as components of a TIN collection shall fulfil the generic consistency rules provided for vector objects. U.K.
1.7.5. Requirements on reference systems U.K.
(1) For measuring the depth of the sea floor where there is an appreciable tidal range (tidal waters), the Lowest Astronomical Tide (LAT) shall be used as reference surface. U.K.
(2) For measuring the depth of the sea floor in marine areas without an appreciable tidal range, in open oceans and in waters that are deeper than 200 meters, the depth of the sea floor shall be referenced to the Mean Sea Level (MSL), or to a well-defined reference level close to the MSL. U.K.
(3) The height of the reference level to which the depth of the floor of an inland water body is measured shall be referred to a gravity-related vertical reference system. This shall be the European Vertical Reference System (EVRS) for the areas within the geographical scope of EVRS, or the gravity-related vertical reference system identified by the Member State outside the scope of EVRS. U.K.
(4) When providing an integrated land-sea elevation model, only one elevation property (either height or depth) shall be modelled, and its values shall be referenced to a single vertical coordinate reference system. U.K.
1.7.6. Requirements on data quality and consistency U.K.
(1) If measures other than ISO data quality measures have been used to evaluate an elevation data set, the Lineage metadata element shall include information about those measures and, if possible, a reference to an online resource where more information is available. U.K.
(2) Connected contour line spatial objects shall have the same elevation value when they are referenced to the same vertical coordinate reference system. U.K.
(3) When the elevation values of break line spatial objects are given as third coordinates (Z), the intersection point of two break line spatial objects shall have the same elevation value. U.K.
(4) When a contour line spatial object and a break line spatial object provided in the same vertical coordinate reference system intersect each other, the intersection point shall have the same elevation value (if the elevation values of break line spatial objects are given by the third (Z) coordinate). U.K.
(5) Contour line spatial objects having different elevation value shall neither intersect nor touch each other when they are referenced to the same vertical coordinate reference system. U.K.
(6) The boundary of an isolated area spatial object shall not touch the external boundary of a void area spatial object when they are referenced to the same vertical coordinate reference system.] U.K.