Projection WGS84 in decimal degree

[Frank Warmerdam]

On 1/11/06, Ed McNierney <ed at topozone.com> 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,
--
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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