[Fwd: Re: WFS gurus . . . .]

[Frank Warmerdam]

Bob Basques wrote:
> All,
> 
> Some progress,
> 
> We've managed to add to the PROJ4 EPSG list and verified that it works 
> with a WMS output.  So the new EPSG code we added works just fine as a 
> WMS call.
> 
> Next we tried the same with a WFS call and got an INIT error, which was 
> traced to OGR, so we then (tried to) build Mapserver without GDAL only 
> to learn that WFS requires it to build.  So my question is, where is OGR 
> grabbing it's Projection info from?  From the code it looks like there 
> is a parser in place, but we couldn't find where it was being referenced.

Bob,

OGR creates it's EPSG coordinate system information from the pcs.csv and
gcs.csv tables distributed with GDAL.  Note that periodically these
tables are regenerated from the EPSG database, and these .csv files are
the basis of generating the PROJ.4 epsg translation file.

In theory you can extend the pcs.csv with your projections but the format
is a bit esoteric.

I believe you can add Well Known Text format definitions to the "epsg.wkt"
file in gdal/data to add stuff not in the pcs.csv and gcs.csv files though
I haven't used this mechanism for a while.  This is what I use to add
Cubewerx and ESRI extensions to the EPSG dataset.

See gdal/data/cubewerx_extra.wkt for examples of how the definitions would
be formatted.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | President OSGF, http://osgeo.org