Andrea Battisti wrote:
Hi list!I am testing a geotiff file which is in the following coordinate system (from gdalinfo...): Coordinate System is: PROJCS["SIN E019", GEOGCS["unnamed", DATUM["unknown", SPHEROID["unretrievable - using WGS84",6378137,298.257223563]], PRIMEM["Greenwich",0], UNIT["degree",0.0174532925199433]], PROJECTION["Sinusoidal"], PARAMETER["longitude_of_center",-82], PARAMETER["false_easting",0], PARAMETER["false_northing",0], UNIT["metre",1, AUTHORITY["EPSG","9001"]]] The earth model used in the "SIN E019" should be an ideal sphere with radius (m): 6370997, but it is not recognized and the WGS84 is used instead. This leads to unwanted offsets on the projected image. Is there a way to tell GDAL to use a specific model when it encounters a specific coordinate system?
Andrea, Briefly, no. There is no way to have GDAL recognise something like "SIN E019" and override the SPHEROID. But there are ways of manually overriding the coordinate system on a file. For instance, create a well known text file of the coordinate system you want to use and doing: gdal_translate in.pix -a_srs fixed.wkt out.tif The above coordinate system was obviously originally from PCI. Did you get it directly from a PCIDSK file, or from an intermediate GeoTIFF file? the gdal/ogr/ogr_srs_pci.cpp code already knows that E019 is a normal sphere, so I would expect it to get expanded properly if coming from a PCIDSK file (or anything else like PAux using pci coordinate system translation). If it came from a GeoTIFF file, then I would have expected PCI to write the proper spheroid info into the geotiff file, and for GDAL to pick it up. If this is the situation, I'd appreciate seeing a "listgeo" report on the file. Listgeo is part of libgeotiff and should be available in FWTools distributions. Best regards, -- ---------------------------------------+-------------------------------------- I set the clouds in motion - turn up | Frank Warmerdam, [EMAIL PROTECTED] light and sound - activate the windows | http://pobox.com/~warmerdam and watch the world go round - Rush | Geospatial Programmer for Rent _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
