Le jeudi 08 février 2007 à 09:55 +0100, Andrea Aime a écrit : > I'd say, if we don't want to compare metadata, not even names should be > considered, but only the ellipsoid parameters and the bursa-worlf > transform (provided the latter is available)?
No. Two datum with the same ellipsoid may be really different things. The datum describes how the ellipsoid is "attached" to the earth. We may have the same ellipsoid, but the ellipsoid may be slightly translated or rotated (while having the same axis length) in one datum compared to an other datum. The datum name is currently the only way to differenciate two datum. This is not specific to Geotools, see: http://gdal.velocet.ca/~warmerda/wktproblems.html (The link doesn't seem to work for me right now, so I'm not completly sure that it is the right link). The workaround is to define a list of aliases. Geotools defines such a list there: http://svn.geotools.org/geotools/trunk/gt/modules/library/referencing/src/main/resources/org/geotools/referencing/factory/DatumAliasesTable.txt For example the first line tell us that datum with name "Abidjan 1987", Abidjan_1987" and "D_Abidjan_1987" are considered equivalent. If you have the name of datum that should be considered equivalent, we could add them to this list. Martin ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier. Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Geotools-devel mailing list Geotools-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/geotools-devel
