[Proj] Stereo 1970 (EPSG 31700)

Frank Warmerdam warmerdam at pobox.com
Mon Oct 4 09:33:36 EST 2010

Thibaut Gheysen wrote:
> Hi,
> I have a problem in QGIS with the Stereo 1970 coordinate system (EPSG 
> 31700).
> I have a shapefile in the WGS 84 coordinate system (from a GPS device). 
> I projected this shapefile in Stereo 1970 using ArcMap.
> In ArcMap, the source and projected points are in the same place. In 
> Qgis, I have a deviation of about 100 meters when displaying this 2 
> shapefiles and activating the "on the fly projection" (stereo.jpg). This 
> deviation is the same that the one I obtain in ArcMap without 
> "geographic coordinate system transformations".


I'm not sure exactly what version of PROJ.4 you are using, but after my
"datum shift identification upgrade" the EPSG dictionary for proj now
has this as the suggested definition of 31700:

+proj=sterea +lat_0=46 +lon_0=25 +k=0.99975 +x_0=500000 +y_0=500000 
+ellps=krass +towgs84=28,-121,-77,0,0,0,0 +units=m +no_defs

Perhaps you could try with this?

Best regards,
I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | Geospatial Programmer for Rent

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