On 1/11/06, Ed McNierney <[EMAIL PROTECTED]> wrote: > > FP - > > Your first GPS layer definition should be fine. You don't say what data > source you are using for your GPS data, but if it is a shapefile or inline > features you will be using decimal degrees and those will work fine with the > "init=epsg:4326" definition. > > The first thing I would suggest is that you confirm that the EPSG:27582 > projection is in fact correct. The related Paris / Lambert projections > (27581-27584, for example) are all rather similar and can certainly look the > same. Can you check the coordinates of a few points to make sure they're > accurate? An error of 200km is far too large to be a datum error, but could > easily be due to the different false easting/northing values used in these > similar projections.
FP, I would add to Ed's comments that the PROJ definitions files for EPSG zones with alternate prime meridians are often messed up, and a horizontal offset of 250km is approximately the distance of the paris meridian from greenwich. 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
