[Proj] cs2cs: Gauss-Krüger to WGS84

Martin Trautmann traut at gmx.de
Mon Dec 10 09:28:36 EST 2012


On 12-12-10 15:08, Andre Joost wrote:
> Am 10.12.12 12:09, schrieb Martin Trautmann:

>> That's not what I did? I thought that

>> 	+towgs84
>> would include the system2 part.
> 
> No. +towgs84 is not the same as +to +init=epsg:4326
> Using EPSG codes, the +towgs84 is hidden inside the code number.

Found it now in epsg:<4326>, while there seem to be many others withn
the same behavior.

>>> At least this point is in Germany... The datum transformation parameters
>>> used are the following:
>>> +towgs84=598.1,73.7,418.2,0.202,0.045,-2.455,6.7
>>
>> That's done automagically? Or do I have to apply this anywhere?
>>
> 
> It is implemented in EPSG:31468 (if you have a current proj), but not in 
> world:gk4-d.


Hm, I thought I got the latest release Rel. 4.8.0, 6 March 2012
- but mine does show
# DHDN / 3-degree Gauss-Kruger zone 4
<31468> +proj=tmerc +lat_0=0 +lon_0=12 +k=1 +x_0=4500000 +y_0=0
+datum=potsdam +units=m +no_defs  <>

... and I would have expected that the "to" wgs84 would not apply for
the from (system 1).

Thanks!
Martin


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