[Proj] converting epsg 25832 to epsg 31467

[Oscar van Vlijmen]

> From: porath-web.de
> Date: Tue, 12 Dec 2006 16:54:21 +0100
> Subject: [Proj] converting epsg 25832 to epsg 31467

> i want to transform coordinates from epsg 25832 to epsg 31467. I don't really
> know about whats going on behind the scenes of proj, so i tried the following:
> 
> cs2cs +init=epsg:25832 +to +init=epsg:31467 <<EOF
> 32536852 5690425
> EOF
> cs2cs returns "*       * 0.00" for my coordinate. What am i doing wrong? I
> expect "3536939 5692262 0.00".

First of all it would be convenient to drop the zone number in the x, so use
536852 instead of 32536852.
Then: perform an explicit datum transformation from the lat,lon obtained on
GRS80 to lat,lon on Bessel 1841. I used the ArcGIS set DHDN_To_ETRS_1989_3.
Mind the direction; the parameters are from DHDN to ETRS - which is close
enough to GRS80. The rotation model is the same as cs2cs does: position
vector.
Description of the set:
dx=597.1; dy=71.4; dz=412.1; rx=0.894; ry=0.068; rz=-1.563; ds=7.58;
Units in meters, arcseconds, ppm.
After datum transform, project with TM.

My results (some decimals dropped in the display, not in the calculation):

Start with x=536852; y=5690425;
Inverse project: lat,lon on GRS80 = 51.363889, 9.529338 deg
Datumtransform to Bessel: lat,lon = 51.365190, 9.530488, h = -45.879 m
Project to TM: 3536941.34, 5692262.52
Expected values: 3536939 5692262
Differences probably due to rounding or a slightly different parameter set.

How to perform this procedure on the cs2cs command line?
Please read the manual or ask mr. Warmerdam to write an extensive tutorial
with 200 boilerplate examples (this would reduce the traffic in the maptools
and other lists some non-vanishing amount!)