[Proj] Stereo 1970 (EPSG 31700)

[Thibaut Gheysen]

Thanks Frank.
I use QGis 1.5 from osgeo4w (I don't know exactly which version of Proj.4 is
used).
I just try with your suggested definition. It's better but I always have a
deviation of about 5 meters.

Thibaut.

2010/10/4 Frank Warmerdam <warmerdam at pobox.com>

> 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".
>
> Thibault,
>
> 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<http://pobox.com/%7Ewarmerdam>
> and watch the world go round - Rush    | Geospatial Programmer for Rent
>
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