GDAL gets southern UTM coordinates wrong (EPSG)

[Markus Neteler]

Hi Frank,

I have the impression that GDAL gets UTM coordinates on southern
hemisphere wrong. I was using LANDSAT-TM5 data from Botswana which
is UTM zone 34S.

ftp://ftp.glcf.umiacs.umd.edu/glcf/Landsat/WRS2/p174/r073/p174r73_5t900416.TM-EarthSat-Orthorectified/
p174r73_5t900416_nn1.tif.gz
gdalinfo p174r73_5t900416_nn1.tif
Driver: GTiff/GeoTIFF
Size is 8191, 7172
Coordinate System is:
PROJCS["WGS 84 / UTM zone 34N",
    GEOGCS["WGS 84",
        DATUM["WGS_1984",
            SPHEROID["WGS 84",6378137,298.2572235629972,
                AUTHORITY["EPSG","7030"]],
            AUTHORITY["EPSG","6326"]],
        PRIMEM["Greenwich",0],
        UNIT["degree",0.0174532925199433],
        AUTHORITY["EPSG","4326"]],
    AUTHORITY["EPSG","32634"],
    PROJECTION["Transverse_Mercator"],
    PARAMETER["latitude_of_origin",0],
    PARAMETER["central_meridian",21],
    PARAMETER["scale_factor",0.9996],
    PARAMETER["false_easting",500000],
    PARAMETER["false_northing",0],
    UNIT["metre",1,
        AUTHORITY["EPSG","9001"]]]
Origin = (701128.500000,-1977985.500000)
Pixel Size = (28.500000,-28.500000)
Corner Coordinates:
Upper Left  (  701128.500,-1977985.500) ( 22d53'54.03"E, 17d52'49.72"S)
Lower Left  (  701128.500,-2182387.500) ( 22d55'9.01"E, 19d43'36.50"S)
Upper Right (  934572.000,-1977985.500) ( 25d 5'55.19"E, 17d50'47.82"S)
Lower Right (  934572.000,-2182387.500) ( 25d 8'36.64"E, 19d41'21.06"S)
Center      (  817850.250,-2080186.500) ( 24d 0'54.24"E, 18d47'20.73"S)
Band 1 Block=8191x1 Type=Byte, ColorInterp=Gray
  Overviews: 1024x897

The GRASS definition for this area is (boundary only approximately):
g.region rast=markveggy.shp.recl -p
projection: 1 (UTM)
zone:       -35
datum:      ** unknown (default: WGS84) **
ellipsoid:  wgs84
north:      8038290
south:      7802760
west:       101850
east:       360510
nsres:      30
ewres:      30
rows:       7851
cols:       8622

GDAL should report EPSG 32734 instead of EPSG 32634.
Or are the data tags corrupted (then NASA, GLCF makes it wrong!)?

Thanks,

 Markus

[neteler@…]

Frank,

while trying to find a quick solution for me, I have thought of 'gdalwarp'
to warp the from UTM34N to UTM34S:

gdalinfo p174r73_5t900416_nn1.tif | grep EP
                AUTHORITY["EPSG","7030"]],
            AUTHORITY["EPSG","6326"]],
        AUTHORITY["EPSG","4326"]],
    AUTHORITY["EPSG","32634"],             <---- ! UTM 34 N
        AUTHORITY["EPSG","9001"]]]

Perhaps GDAL is right on that and the data are wrong. Anyway, here
the warping:

gdalwarp -s_srs EPSG:32634 -t_srs EPSG:32734 p174r73_5t900416_nn1.tif
p174r73_5t900416_nn1_UTM34S.tif
Creating output file is that 8191P x 7172L.
:0...10...20...30...40...50...60...70...80...90...100 - done.

gdalinfo p174r73_5t900416_nn1_UTM34S.tif
Driver: GTiff/GeoTIFF
Size is 8191, 7172
Coordinate System is `'
Corner Coordinates:
Upper Left  (    0.0,    0.0)
Lower Left  (    0.0, 7172.0)
Upper Right ( 8191.0,    0.0)
Lower Right ( 8191.0, 7172.0)
Center      ( 4095.5, 3586.0)
Band 1 Block=8191x1 Type=Byte, ColorInterp=Gray

-> It "eats" the coordinate system, only XY coordinates are left
over...silently. Is that a bug or feature?


Then I thought it doesn't make sense to specify -s_srs EPSG:32634
as the data set already contains this information:

gdalwarp -t_srs EPSG:32734 p174r73_5t900416_nn1.tif    
p174r73_5t900416_nn1_UTM34S.tif
:0...10...20...ERROR 1: latitude or longitude exceeded limits
ERROR 1: latitude or longitude exceeded limits
ERROR 1: latitude or longitude exceeded limits
ERROR 1: latitude or longitude exceeded limits
ERROR 1: latitude or longitude exceeded limits
ERROR 1: latitude or longitude exceeded limits
ERROR 1: latitude or longitude exceeded limits
ERROR 1: latitude or longitude exceeded limits
ERROR 1: latitude or longitude exceeded limits
ERROR 1: latitude or longitude exceeded limits
ERROR 1: latitude or longitude exceeded limits
ERROR 1: latitude or longitude exceeded limits
ERROR 1: latitude or longitude exceeded limits
ERROR 1: latitude or longitude exceeded limits
ERROR 1: latitude or longitude exceeded limits
ERROR 1: latitude or longitude exceeded limits
ERROR 1: latitude or longitude exceeded limits
ERROR 1: latitude or longitude exceeded limits
ERROR 1: latitude or longitude exceeded limits
ERROR 1: Reprojection failed, err = -14, further errors will be supressed on the
transform object.
30...40...50...60...70...80...90...100 - done.

Also this leads to (only) XY coordinates.

Kind regards

 Markus

[warmerdam]

Markus,

Both of the things you did worked fine for me.  The writing of the
output SRS was implemented Dec 17 in gdalwarp.c, perhaps you didn't have it.