[GRASS-user] more on misaligned rasters vs vectors

[Kirk Wythers]

First a quick recap on the problem including suggestions from list. 

Problem:

I imported three files (two shape files with v.in.ogr, and one .img file with r.in.gdal). All files purport to be alberrsequalarea projections and come from independent sources. Also, after reading the metadata for each file, the projections and geographic information appears identical for each file.  

All files were imported into an albers locatiog.region and while the two shape files appear correct (are properly aligned), while the raster (the .img) is shifted approximately 1600 km north. I checked the info for false northing on each file and they all report 0.000000 for false northing. 

Here is the kicker... a colleague imported the same files into ArcMap, and all three appear correct. His take was that maybe grass is reading the metadata for the .img file in an odd way... my take is that I'm probably doing something wrong. Or perhaps ArcMap is ignoring something that r.in.gdal is reading. 

Below I have included the output from g.proj, g.region, r.info and v.info (maybe some one can see something I am missing). Any ideas as to what else I should check would be appreciated. 

Thanks for help



GRASS 6.4.1 (northcentralus_albersequalarea):~ > g.proj -p
-PROJ_INFO-------------------------------------------------
name       : Albers Equal Area
proj       : aea
datum      : nad83
ellps      : grs80
lat_1      : 29.5
lat_2      : 45.5
lat_0      : 23
lon_0      : -96
x_0        : 0
y_0        : 0
no_defs    : defined
-PROJ_UNITS------------------------------------------------
unit       : meters
units      : meterss
meters     : 1
GRASS 6.4.1 (northcentralus_albersequalarea):~ > g.region -p
projection: 99 (Albers Equal Area)
zone:       0
datum:      nad83
ellipsoid:  grs80
north:      2960848
south:      2087348
west:       -122110
east:       1141890
nsres:      250
ewres:      250
rows:       3494
cols:       5056
cells:      17665664

r.info and v.info for each file give:

GRASS 6.4.1 (northcentralus_albersequalarea):~ > r.info mnwimifnfftgk7wt175v3_250m
+----------------------------------------------------------------------------+
| Layer:    mnwimifnfftgk7wt175v3_250m     Date: Fri Oct 14 11:10:29 2011    |
| Mapset:   lake_states                    Login of Creator: kirkw           |
| Location: northcentralus_albersequalarea                                   |
| DataBase: /Volumes/disk1/home1/kirkw/grassdata                             |
| Title:     ( mnwimifnfftgk7wt175v3 )                                       |
| Timestamp: none                                                            |
|----------------------------------------------------------------------------|
|                                                                            |
|   Type of Map:  raster               Number of Categories: 999             |
|   Data Type:    CELL                                                       |
|   Rows:         3494                                                       |
|   Columns:      5056                                                       |
|   Total Cells:  17665664                                                   |
|        Projection: Albers Equal Area                                       |
|            N:    2960848    S:    2087348   Res:   250                     |
|            E:    1141890    W:    -122110   Res:   250                     |
|   Range of data:    min = 0  max = 999                                     |
|                                                                            |
|   Data Description:                                                        |
|    generated by r.in.gdal                                                  |
|                                                                            |
|   Comments:                                                                |
|    r.in.gdal input="/Volumes/disk1/home1/kirkw/Desktop/mnwimifnfftgk7wt\   |
|    175v3.img" output="mnwimifnfftgk7wt175v3"                               |
|                                                                            |
+----------------------------------------------------------------------------+


GRASS 6.4.1 (northcentralus_albersequalarea):~ > v.info nw212
+----------------------------------------------------------------------------+
| Layer:           nw212                                                     |
| Mapset:          lake_states                                               |
| Location:        northcentralus_albersequalarea                            |
| Database:        /Volumes/disk1/home1/kirkw/grassdata                      |
| Title:                                                                     |
| Map scale:       1:1                                                       |
| Map format:      native                                                    |
| Name of creator: kirkw                                                     |
| Organization:                                                              |
| Source date:     Tue Nov 15 08:14:37 2011                                  |
|----------------------------------------------------------------------------|
|   Type of Map:  vector (level: 2)                                          |
|                                                                            |
|   Number of points:       0               Number of areas:      13         |
|   Number of lines:        0               Number of islands:    5          |
|   Number of boundaries:   20              Number of faces:      0          |
|   Number of centroids:    7               Number of kernels:    0          |
|                                                                            |
|   Map is 3D:              No                                               |
|   Number of dblinks:      1                                                |
|                                                                            |
|         Projection: Albers Equal Area                                      |
|               N:      1322833.8573    S:       647305.3646                 |
|               E:      1003361.9406    W:         6150.4319                 |
|                                                                            |
|   Digitization threshold: 0                                                |
|   Comments:                                                                |
|                                                                            |
+----------------------------------------------------------------------------+