Hi,

I have a question about the units of the parameters at the TOWGS84 WKT tag 
respectively OGRSpatialReference::SetTOWGS84(…)

ESRI and ERDAS specify the TOWGS84 rx, ry and rz paramters in radians, whereas 
GDAL seems to be expecting them in arcseconds.

DHDN for example is defined by ESRI and ERDAS with 
TOWGS84[598.1,73.7,418.2,-9.793000000000001e-007,-2.182e-007,1.19e-005,6.7e-006]
which seems to give a wrong result in GDAL. 
If I change it to
TOWGS84[598.1,73.7,418.2,0.202,0.045,-2.455,6.7]
it looks right.

Is arcseconds the recommended unit and ESRI and ERDAS don’t stick to the 
convention or should I always recalculate the TOWGS84 parameters and set them 
manually with OGRSpatialReference::SetTOWGS84(…) ?

Thanks for helping,
Thomas

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