Thanks Jean-Claude, I was using EPSG:900913 for the OSM tiles and Googled about it looking for the +towgs84 parameter but couldn't find anything. I did find several posts about EPSG:3785 being the same as EPSG:900913 and that one does have the +towgs84 parameter. Should I use that proj4 string instead? +proj=merc +lon_0=0 +k=1 +x_0=0 +y_0=0 +a=6378137 +b=6378137 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs
And how about the custom projection? Do you have any idea how to create a proj4 style string from that? Thanks, Paul 2010/7/14 Jean-Claude REPETTO <jrepe...@free.fr> > Hi, > > > On 07/14/10 11:54, Paul Meems wrote: > >> >> I'm using this proj4 string for the OSM tiles: >> +proj=merc +lon_0=0 +lat_ts=0 +x_0=0 +y_0=0 +a=6378137 +b=6378137 >> +units=m +no_defs >> >> > This one is not correct if you want to do a datum transformation : the > +towgs84 parameter is missing. > > Jean-Claude > _______________________________________________ > gdal-dev mailing list > gdal-dev@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/gdal-dev >
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