[FWTools] datum shifting in FWTools

Frank Warmerdam warmerdam at pobox.com
Mon Oct 20 23:01:52 EDT 2008

Roger André wrote:
> Is it possible in FWTools to use a projection which specifies the 
> following, "+nadgrids=@null"?


Yes, it should work with the FWTools PROJ.4 tools (and related stuff
like MapServer).  If you want to use it with GDAL and OGR it is a bit
more involved.  I think you need to add +wktext in the PROJ.4 definition
so that GDAL will "capture" the literal PROJ.4 definition in the internal
WKT representation so the nadgrids part won't get lost.

Best regards,
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    | Geospatial Programmer for Rent

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