[Proj] *SOLVED*: Creating a nadgrid shift file with GDAL

[Jan Hartmann]

On 01/22/2013 04:19 PM, Andre Joost wrote:
> Am 21.01.2013 15:12, schrieb Jan Hartmann:
>
>> 5) create two point files, one for the lons and one for the lats. The
>> coordinates should be the wgs84 values, and the z-value the lon or lat.
>
> I think you made a mistake there, or not stated it clearly.
> According to the Beta2007 specification, the grid is related to the
> *source* CRS ellipsoid, that is EPSG:4289 Amersfoort latlon for
> EPSG:28991 and 28992, and EPSG:4314 DHDN for German Gauss-Krüger CRS.
>
> The shift values are from bessel ellipsoid (or Airy, Clarke or whatever)
> to the WGS84 ellipsoid. For reprojection, an iterative solution is
> mentioned.
>
>
I think you are right (Hermann Peifer pointed out the same thing). I do 
not understand your reference to epsg:4289, though: that epsg number has 
a wgs84 shift. The original ellipsoid for Amersfoort is jus Bessel, so 
the source latlon epsg would be 4308

Jan
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