[GRASSLIST:10027] projection problems

[Kirk R. Wythers]

It seems that I could use some very basic explanation concerning  
locations and projections. I am trying to read several shape files  
into a single location. However, I am getting a projection error on  
some of them.

g.region -p for the location is:

GRASS 6.1.cvs (minnesota_utm):~ > g.region -p
projection: 1 (UTM)
zone:       15
datum:      nad83
ellipsoid:  grs80
north:      5472415.17999963
south:      4816310.42
west:       189788.954
east:       761663.27300056
nsres:      0.99999963
ewres:      1.00000056
rows:       656105
cols:       571874

and v.info for the state outline shape file (which read in fine with  
v.in.ogr) is:

GRASS 6.1.cvs (minnesota_utm):~ > v.info mn_state
+----------------------------------------------------------------------- 
-----+
| Layer:    mn_state                        
Organization:                     |
| Mapset:   pls                            Source  
Date:                      |
| Location: minnesota_utm                  Name of  
creator:                  |
| Database: /Volumes/disk1/home1/kwythers/ 
grassdata                          |
|  
Title:                                                                   
    |
| Map Scale:   
1:1                                                            |
| Map format:  
native                                                         |
|----------------------------------------------------------------------- 
-----|
|   Type of Map:  Vector (level:  
2)                                          |
|                                                                        
      |
|   Number of points:       0               Number of areas:       
1          |
|   Number of lines:        0               Number of islands:     
1          |
|   Number of boundaries:   1               Number of faces:       
0          |
|   Number of centroids:    1               Number of kernels:     
0          |
|                                                                        
      |
|   Map is 3D:               
0                                                |
|   Number of dblinks:       
1                                                |
|                                                                        
      |
|   Projection: UTM (zone  
0)                                                 |
|            N: 5472414.182    S:  
4816310.425                                |
|            E: 761662.273    W:  
189788.954                                  |
|            B: 0.000         T:  
0.000                                       |
|                                                                        
      |
|   Digitize threshold:  
0.00000                                              |
|    
Comments:                                                                
  |
|                                                                        
      |
+----------------------------------------------------------------------- 
-----+

Although I do notice that the projection reads UTM (zone 0) which  
seems odd to me... it should be zone 15.

Now for the really fun part...

If I try and read another shape file into the location, I get the  
projection error about not matching the current location:

GRASS 6.1.cvs (minnesota_utm):~ > v.in.ogr dsn=~/projects/mn_dnr/ 
shape_files/pls_corners_btrees/county/cook/ output=cook_test
ERROR: Projection of dataset does not appear to match current location.

        LOCATION PROJ_INFO is:
        name: UTM
        datum: nad83
        towgs84: 0.000,0.000,0.000
        proj: utm
        ellps: grs80
        a: 6378137.0000000000
        es: 0.0066943800
        f: 298.2572221010
        zone: 15

        cellhd.proj = 0 (unreferenced/unknown)

        You can use the -o flag to v.in.ogr to override this check.
        Consider to generate a new location with 'location' parameter  
from
        input data set.

If I use the -o flag (or location=some_new_location) the file comes  
in as projection (0) x,y

I asked one of our ARC/GIS folks downstairs to see if he could import  
the shape files and lay them on top of each other and he did not have  
any trouble. I am wondering if I have set something very basic up wrong.

Any suggestions for diagnosing this problem and getting these shape  
files to match up would be much appreciated.

Thanks