[Proj] Offset when converting coordinates from ESRI:31700 to EPSG:4326

[Jean-Claude Repetto]

Le 22/04/2011 10:57, Adrian Popa a écrit :
> I have a problem when converting coordinates from ESRI:31700 (Stereo 70)
> to WGS84 (EPSG:4326). The coordinates I get from the conversion have an
> offset from the original coordinate of about 50m.
>
> My ESRI/EPSG definitions are as follows:
>
> EPSG:
> # Dealul Piscului 1970/ Stereo 70 (deprecated)
> <31700>  +proj=sterea +lat_0=46 +lon_0=25 +k=0.99975 +x_0=500000
> +y_0=500000 +ellps=krass +units=m +no_defs<>
> # WGS 84
> <4326>  +proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs<>
>
> ESRI:
> # Dealul Piscului 1970/ Stereo 70
> <31700>  +proj=stere +lat_0=46 +lon_0=25 +k=0.999750 +x_0=500000
> +y_0=500000 +ellps=krass +units=m +no_defs  no_defs<>
>
> Can anybody clue me in as to what I'm doing wrong?

Both definitions are missing the +towgs84 parameters.

Jean-Claude