[Geotiff] Proposed TOWGS84 GeoKey for GeoTIFF

[Christian Zietz]

Frank Warmerdam schrieb:

> It has been an irritant to me for some time that there is no way of
> recording a preferred datum transformation for a coordinate system in
> GeoTIFF format.  I would like to rectify that with an unofficial GeoKey
> to record OGC WKT style TOWGS84 values.  I have written up a brief
> proposal at:
> 
>    http://trac.osgeo.org/geotiff/wiki/TOWGS84GeoKey

Let me add that the test file I prepared while proposing this feature
still exists at <http://www.chzsoft.de/geo/GeogToWGS84GeoKey5.zip>.