From: Daniele R. <dan...@ge...> - 2008-05-29 10:55:14
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Hi lists, I have another question about VerticalExtent. As already stated in my previous email titled "Multidimensional Coverage and Vertical Extent", part of my job is related to handling the Extent of a 4D Coverage (XY+Vertical+Temporal). In such a context, ISO 19115 defines the EX_Extent element which is extended by GeographicBoundingBox (holding northing,southing,westing,easting geographic boundaries), TemporalExtent and VerticalExtent. The latter is related to a VerticalCRS (as defined in 19111) which can't be used to handle ellipsoidal height since this height only lives within a 3D GeographicCRS. Under these conditions, how should I handle the 3rd component of a GeographicCRS to follow the 19115/19111? I just have acquired the 19115:2003 corrigendum 2006 which, for VerticalExtent, has removed the verticalDatum element changed to verticalCRS. Consequently SC_VerticalDatum class has been changed to SC_CRS with the note "SC_CRS: set of parameters describing the relation of gravity-related heights to the Earth". Now I'm not sure about the meaning of that SC_CRS. It is referring to a general CRS containing a "height related" component (Such as a 3D GeographicCRS or a CompoundCRS)?. Or the SC_CRS has been used to indicate the base class of a VerticalCRS to point out that the Datum class is no more needed)? Maybe the ISO 19115 VerticalExtent could be related to a more general CoordinateReferenceSystem within it lives instead of a VerticalCRS. Best Regards, Daniele -- ------------------------------------------------------- Eng. Daniele Romagnoli Software Engineer GeoSolutions S.A.S. Via Carignoni 51 55041 Camaiore (LU) Italy phone: +39 0584983027 fax: +39 0584983027 mob: +39 328 0559267 http://www.geo-solutions.it ------------------------------------------------------- |