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EL GridCoverage Model - CV_Grid:extent or CV_Grid:limits

    Johanna Ott
    By Johanna Ott Replies (2)

    Hi everybody,

    I am rather new to the Coverages subject and am right now working on transforming Elevation data into the INSPIRE Elevation GridCoverage model.

    I have a question concerning the domainSet-attribute of the ElevationGridCoverage-FeatureType: The Data Specification (section 5.5.1.2.2.) mentions the attribute CV_RectifiedGrid:extent (which it inherits from CV_Grid according to the UML diagram of OI https://inspire.ec.europa.eu/data-model/approved/r4618-ir/html/index.htm?goto=2:2:4:1:1:7835 - this association is not diaplayed in the UML diagram of EL, which is why I am reffering to OI here). In contrast to that, "extent" cannot be found in the corresponding xsd (http://schemas.opengis.net/gml/3.2.1/grids.xsd#0:0). It seems that it has been replaced by CV_Grid:limit?.

    I could not find any part in the Data Specification or any thread in this Cluster, that explains, why that is the case. Could someone help me out and explain to me, why the xsd differs from the model representation?

     

    Thank you in advance and all the best

    Johanna

      • Enrico Iredi

        Hello Johanna,

        the rectified grid attribute looks like this. There is no extent?

        Sample coverage: https://themes.jrc.ec.europa.eu/file/view/214982/gml-example-renewableandwastepotentialcoverage-er-c

        Best regards

        Enrico

        • Johanna Ott

          Hello Enrico,

          Thank you for the reply. Exactly, as I mentioned, in the XSD, there is no extent attribute. But looking at this UML diagram, I would expect one in CV_RectifiedGrid:

          (the diagram extract is taken from the OI specification - figure 8 as the EL specification is less deteiled there).

          Also, section 5.5.1.2.2. of the EL Data Specification mentions an extent attribute: "By inheritance from RectifiedGridCoverage, the value type is restricted to CV_RectifiedGrid. This ISO 19123 element allows defining the characteristics of the internal grid structure: the grid dimension, which is constrained to two (CV_RectifiedGrid::dimension), the extent which reports the extreme internal grid coordinates of the DEM (CV_RectifiedGrid::extent) and the names the grid axes (CV_RectifiedGrid::axisNames)."

          That is why I am confused there is no extent in the XSD.

        Elevation, Ortho & Grids

        Elevation, Ortho & Grids

        INSPIRE Thematic Cluster Elevation, Orthoimagery, Reference systems, Geographical grids - Join this group to share your knowkledge, learn and collaborate in solving issues related to the Elevation, Orthoimagery, Reference systems and Geographical grids themes