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<font face="Times New Roman, Times, serif">(Sorry for crossposting,
don't know if it is a gdal or proj problem )<br>
<br>
This has been discussed on this list some time ago. I have been
able to create a working nadgrid file with gdal, but it doesn't
return the right coordinates. I did it as follows:<br>
<br>
- create a 4 band, float32 geotif, each pixel with the
displacements in lat, lon (arcseconds), errorx and errory (both
zero)<br>
- gdal-translate it to ntv2-format.<br>
<br>
The displacements in the geotiff are correct, and proj returns
shifted coordinates when using the ntv2-file, but not on the right
location. I'm really out of my wits. Could it have something to do
with ntv2 using negative lon-values east of Greenwich? Any help
would be appreciated.<br>
<br>
Jan </font><br>
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