ED50 (TURKEY) Datum Transformation Parameters

Alan_D

Hi,
We have been experiencing transformation issues with using Turkish data. I am trying to determine correct transformation parameters for ED50 (TURKEY) to WGS84.

GM uses the following values;
X-axis translation = -84.83
Y-axis translation = -103.97
Z-axis translation = -127.45
X-axis rotation = -0.1715
Y-axis rotation = 0
Z-axis rotation = 0.3995
Scale difference = 1.04540
taken from GlobalMapper

However, these values differ from those shown on EPSG Geodetic Parameter Registry and those used in the csmap library.
https://svn.osgeo.org/metacrs/csmap/branches/12.0/CsMapDev/Dictionaries/datums.asc

X-axis translation = -84.1
Y-axis translation = -101.8
Z-axis translation =-129.7
X-axis rotation = 0
Y-axis rotation = 0
Z-axis rotation = 0.468
Scale difference = 1.05

Can anyone please help to explain the difference and to help me understand which parameters I should be using.

Thanks!
Alan