[GRASSLIST:2386] Re: s.proj question

[Frank Warmerdam]

Kevin Slover wrote:
> I am using the s.proj command to reproject some site data, and I am
> curious to the conversion method used.  I am going from nad83 degrees
> (decimal) format to state plane coordinate.  Is it using something
> similar to CORPSON available from the National Geodetic Survey, or is an
> internal program developed by the GRASS programmer??  Thanks...

Kevin,

GRASS uses an internal copy of the PROJ.4 library developed by the USGS
for projection conversions.  I thought that CORPSON (CORPSCON?) was a
datum shifting package - I guess not?  Note that s.proj (to the best of
my knowledge) does not support doing datum shifting.  This has to be
done with other GRASS programs where possible.

It is my hope that GRASS 5.1 will include datum shifting right from within
the GRASS programs for reprojecting all based on the code in PROJ.4.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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