[GRASS-user] I do not understand how region/projection/coordinate system are intertwined

[Stephen Sefick]

Is the geotiff in degrees?

If you are on unix use gdalinfo to find out the projection of the 
geotiff.  You will have to import in its native projection and then 
reporject into whatever coordinate system that you would like.  I am 
just drinking my coffee this morning, so I may not be awake yet.
HTH,

Stephen

On Wed 14 Mar 2012 02:27:39 AM CDT, Fridtjof Schiefenhövel wrote:
> Hello there!
>
> it seems I can't solve this problem:
>
> ->create a location with a mercator projection (i want to have degrees as the coordinate system)
>
> ->import landsat geotiffs
>
> ->have degrees as units showing (e.g. when moving the mouse)
>
> this is what I did:
>
> -created a location using the projection/datum from a georeferenced file (the landsat geotiff).
>
> -created a location selecting mercator projection
>
> here is what "g.region -p" showed:
> projection: 99 (Mercator)
> zone:       0
> datum:      wgs84
> ellipsoid:  wgs84
> north:      0
> south:      -12.5
> west:       125
> east:       150
> nsres:      12.5
> ewres:      12.5
> rows:       1
> cols:       2
> cells:      2
>
> -ran v.in.region in the source location
> {trying r.proj without it would give me an error saying the imported region is out of bounds}
>
> -imported the vector map in the target location
>
> -set region to imported vector map
>
> -ran r.proj to import/reproject the landsat geotiff from the source location.
>
> here is what "g.region -p" showed now:
> projection: 99 (Mercator)
> zone:       0
> datum:      wgs84
> ellipsoid:  wgs84
> north:      -375086.40793588
> south:      -583681.58556862
> west:       -122131.46631847
> east:       111149.12622161
> nsres:      12.49971103
> ewres:      12.50029968
> rows:       16688
> cols:       18662
> cells:      311431456
>
> I do not understand, how can these bound values be even accepted when I chose Mercator projection and degrees coordinate system in the first place?
>
> Thanks!
>
>
>
>
> _______________________________________________
> grass-user mailing list
> grass-user at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/grass-user

-- 
Stephen Sefick
**************************************************
Auburn University                                         
Biological Sciences                                      
331 Funchess Hall                                       
Auburn, Alabama                                        
36849                                                           
**************************************************
sas0025 at auburn.edu                                  
http://www.auburn.edu/~sas0025                 
**************************************************

Let's not spend our time and resources thinking about things that are 
so little or so large that all they really do for us is puff us up and 
make us feel like gods.  We are mammals, and have not exhausted the 
annoying little problems of being mammals.

                                -K. Mullis

"A big computer, a complex algorithm and a long time does not equal 
science."

                              -Robert Gentleman