[Proj] Re: Proj and Geoitiff

[Frank Warmerdam]

Thomas Flemming wrote:
> Hello,
> 
> does someone knows about the function GTIFGetProj4Defn from the 
> geotiff-lib?
> 
> I have geotiff-maps from
> http://www.granit.sr.unh.edu/cgi-bin/nhsearch?dset=drg/drg162
> which gives no complete proj-parameters from GTIFGetProj4Defn.
> 
> Heres the output from listgeo.exe:
> 
> 
> PCS = 32110 (name unknown)
> Projection = 12830 ()
> GCS: 4269/NAD83
> Datum: 6269/North American Datum 1983
> Ellipsoid: 7019/GRS 1980 (6378137.00,6356752.31)
> Prime Meridian: 8901/Greenwich (0.000000/  0d 0' 0.00"E)
> Projection Linear Units: 9003/(unknown) (1.000000m)
> 
> PROJ.4 Definition: +ellps=GRS80 +units=us-ft

Thomas,

Note, seeing the preceeding messages from listgeo can also be helpful.
What you did supply is summary information extracted from the real keys.

I think the problem you are seeing is that the listgeo executable can't
find the GeoTIFF .csv support files for looking up EPSG coordinate systems.
Here I get the PROJ.4 string that looks like the following for EPSG:32110.

   +proj=tmerc +lat_0=42.5 +lon_0=-71.66666666666667 +k=0.999967 +x_0=300000
       +y_0=0 +ellps=GRS80 +datum=NAD83 +units=m +no_defs

Setting the GEOTIFF_CSV environment variable to point to the directory
with the csv files in it should do the trick.

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