[GRASS-user] point reprojection: v.proj vs cs2cs results

[Maciej Sieczka]

ivan marchesini napisał(a):
> Dear Users,
> 
> I need to reproject a point (280799|4802457) from location A to location
> B
> 
> these are the PROJ_INFO files:
> _______________________
> LOCATION A (UTM ED50)
> 
> name: UTM
> datum: eur50
> towgs84: -87.000,-98.000,-121.000
> proj: utm
> ellps: international
> a: 6378388.0000000000
> es: 0.0067226700
> f: 297.0000000000
> zone: 33
> ______________________
> 
> and
> ______________________
> Location B (Gauss-Boaga EST Rome40)
> 
> name: Transverse Mercator
> datum: rome40
> towgs84: -104.1,-49.1,-9.9,0.971,-2.917,0.714,-11.68
> proj: tmerc
> ellps: international
> a: 6378388.0000000000
> es: 0.0067226700
> f: 297.0000000000
> lat_0: 0.0000000000
> lon_0: 15.0000000000
> k_0: 0.9996000000
> x_0: 2520000.0000000000
> y_0: 0.0000000000
> __________________
> 
> 
> if I try to use v.proj for the point, from location A to Location B,
> I obtain this coordinate (into location B):
> 2300732.60711273|4802279.27423501
> 
> --------------------------------------
> 
> Instead, if I use cs2cs:
> 
> echo "280799 4802457 263" | cs2cs -v +init=epsg:23033 +to +proj=latlong
> +datum=WGS84 |cs2cs -v +proj=latlong +datum=WGS84 +to +init=epsg:3004
> +towgs84=-104.1,-49.1,-9.9,0.971,-2.917,0.714,-11.68

Correct cs2cs syntax would be:

$ echo "280799 4802457 263" | cs2cs +init=epsg:23033
+towgs84=-87.000,-98.000,-121.000 +to +init=epsg:3004
+towgs84=-104.1,-49.1,-9.9,0.971,-2.917,0.714,-11.68

which gives:

2300732.61      4802279.28 265.39

OK?

Maciek