coordinate conversion problem

[Frank Warmerdam]

On Apr 8, 2005 9:52 AM, Didrik Pinte <dpinte at itae.be> wrote:
> Hi,
>
> I'm using a lot of rasters and one shape file in Esri
> NTF_France_Lambert_II coordinates
>
> I've translated NTF_France_Lambert_II in epsg:27572
>
> I will have a layer of GPS points in latlong coordinates. To simulate
> this, I took a shapefile in Esri NTF_France_Lambert_II coordinates and
> convert it using ArcGIS to GCS_WGS_84.
>
> I've translated GCS_WGS_84 to epsg:4326
>
> When I look at the map, my latlong points are nearly 400 km on the left
> of the original points ...
>
> How can I solve the problem ? Did I choosed a bad epsg reference ?
>
> Thank you in advance for your help

Didrik,

There are problems with the translations in PROJ.4 for coordinate systems
with alternate prime meridians, and coordinate systems based on gradians.
One related bug is:

 http://bugzilla.remotesensing.org/show_bug.cgi?id=811

I think there are others in the PROJ.4 bugzilla more specific to your problem.
The gist of it is, you will need to correct the definition manually in your
PROJ.4 "epsg" file.  This is in /usr/local/share/proj/epsg on unix/linux.

Best regards,
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