Hi Jean-Claude, Thanks for the help.
To test the effect that I was getting, I created a total of four images. Two in Sinusoidal projection, using WGS84 and RT90, and another pair using Lambert Equal Area (again with both WGS84 and RT90 datum). I then compared these to an unaltered Equirectangular projected image in WGS84. The results seemed odd and so I've provided them below: The Sinusoidal projections were both 16km from my source, regardless of whether I used RT90 or WGS84. The Lambert projection using WGS84 transformed back perfectly. The Lambert projection using RT90 transformed back with a ~900m error, similar to what was seen when I used Vincent's method above. So it's possible that the +towgs84 parameters are at fault, but then why would the Sinusoidal/WGS84 be as bad as the Sinusoidal/RT90? -- View this message in context: http://osgeo-org.1803224.n2.nabble.com/Require-Help-Transforming-into-Equirectangular-tp5789691p5792571.html Sent from the GDAL - Dev mailing list archive at Nabble.com. _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
