[GRASSLIST:6802] cs2cs and grass

[Francesco Mirabella]

hi to all,
I have a questio regarding the use of cs2cs and v.proj:

I have a point in WGS84 latlong geographic coordinates which was
imported into grass, the PROJ_INFO of the WGS84 location is:
########################
name: Latitude-Longitude
datum: wgs84
towgs84: 0.000,0.000,0.000
proj: ll
ellps: wgs84
########################

then I projected (v.proj) to a gauss-boaga location, the PROJ_INFO is:

########################
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
########################

Just to check,
I tried to project the point from WGS84 to Gauss Boaga using cs2cs:
------------------------
 cs2cs -E +proj=latlong  +datum=WGS84 +to +proj=tmerc +lon_0=15
  +k=0.9996 +x_0=2520000 +ellps=intl  -v -f %.6f
------------------------


After importing the point of check into the Gauss Boaga location, it
results to be shifted about 167 m (mainly to the North) with respect to
the point project (v.proj).

where am I wrong? can anyone help??

Francesco