W dniu 05.02.2011 14:47, Hermann Peifer pisze:
On 05/02/2011 13:12, Even Rouault wrote:
I've just had a look, but not being neither Dutch nor a specialist of (stereographic) projections, I don't feel competent enough to do any action on it. Those tickets plus the reading of http://udig.refractions.net/files/docs/api- geotools/org/geotools/referencing/operation/projection/Stereographic.html make me deeply confused and wondering if r21627 was really appropriate.
Hmm. This page confirms what I mentioned in ticket #2869: "Double_Stereographic" is simply the ESRI alias of "Oblique_Stereographic" (EPSG code 9809). About r21627: I am afraid I do not understand enough about the inner workings of GDAL/OGR to make a judgement about whether this change was appropriate or not. But by the end of the day and from what I remember when looking somewhat deeper into the issue, about 2 years ago: there is one stereographic projection (known as "the USGS formula" or "the approach given by Snyder") which translates into +proj=stere, and there is the other "Double_Stereographic", aka "Oblique_Stereographic" which is expected to end up as +proj=sterea.
I'm not an expert too, but Hermann findings are in accordance with my findings for Polish stereographic CRS (from over 5 years ago): http://lists.maptools.org/pipermail/proj/2005-March/001524.html The Polish CRSs which use +proj=sterea version of stereographic are 3120, 2172-2174, 3328. See also Gerald Evendeen's notes: http://lists.maptools.org/pipermail/proj/2005-March/001526.html Maciek -- Maciej Sieczka http://www.sieczka.org _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
