# [GRASS-user] Which gauss-krueger projection ?

Markus Neteler neteler at osgeo.org
Mon Jun 9 15:55:28 EDT 2008

```On Mon, Jun 9, 2008 at 9:40 PM, Nikos Alexandris
<nikos.alexandris at felis.uni-freiburg.de> wrote:
> On Mon, 2008-06-09 at 21:37 +0200, Markus Neteler wrote:
>> On Mon, Jun 9, 2008 at 9:11 PM, Nikos Alexandris
>> <nikos.alexandris at felis.uni-freiburg.de> wrote:
>> > On Mon, 2008-06-09 at 20:56 +0200, Nikos Alexandris wrote:
>> >> I am trying to define a location based on epsg:31466
>> >>
>> >> A table shows-up which expects a "difficult" choice between 7 options. I
>> >> would like to "cover" the mosel river and part of the "Rheintal".
>> >>
>> >> I would pick the 5th choice (West-Middle) but I rather ask first "why
>> >> the 5th and not the last one which covers the whole of Germany?".
>> >>
>> >> Any German epxerts?
>> >>
>> >>
>> >> Thank you,
>> >>
>> >> Nikos
>> >
>> >
>> > Sorry for not being very clear (and thank you Markus for your interest).
>> >
>> > Attached is a screenshot (a .png file -- not sure if this is allowed in
>> > the mailing list -- but it's not possible to copy-paste from this pop-up
>>
>> The choice is rather easy:
>> - "whole country" has a precision of 3m
>> - the other, regionally optimized zone have better than 1m precision
>>
>> So, you'd better take the one optimized for your region.
>>
>> Markus
>
> My problem is that I am not sure if one of the options (besides the
> whole-country) deals with the bounding box of my interest:
>
> Those are (in metres)
>
> N:           5580000    S:           5490000
> E:           2644000    W:           2534000
>
> And I am not sure whiche transformation parameters to use to convert
> them to degrees ;-)

Better post this a new summary to the PROJ4 list...
In any case, you need to stick to the GK-zones.

Maybe of interest:
http://spatialreference.org/ref/epsg/31466/

Markus
```