[GRASS-user] bug with projection systems?

[Shaun Langley]

Here is the projection for my input file:

Driver: GTiff/GeoTIFF
Files: MOD112_2004_001.LST_Day_1km.tif
Size is 2495, 2504
Coordinate System is:
PROJCS["WGS 84 / UTM zone 36N",
    GEOGCS["WGS 84",
        DATUM["WGS_1984",
            SPHEROID["WGS 84",6378137,298.257223563,
                AUTHORITY["EPSG","7030"]],
            AUTHORITY["EPSG","6326"]],
        PRIMEM["Greenwich",0],
        UNIT["degree",0.0174532925199433],
        AUTHORITY["EPSG","4326"]],
    PROJECTION["Transverse_Mercator"],
    PARAMETER["latitude_of_origin",0],
    PARAMETER["central_meridian",33],
    PARAMETER["scale_factor",0.9996],
    PARAMETER["false_easting",500000],
    PARAMETER["false_northing",0],
    UNIT["metre",1,
        AUTHORITY["EPSG","9001"]],
    AUTHORITY["EPSG","32636"]]

Here is the projection on which I initialized my GRASS location:

Driver: GTiff/GeoTIFF
Files: Mode_LULC_T1_500m.tif
Size is 1792, 2082
Coordinate System is:
PROJCS["WGS_1984_UTM_Zone_36S",
    GEOGCS["WGS 84",
        DATUM["WGS_1984",
            SPHEROID["WGS 84",6378137,298.257223563,
                AUTHORITY["EPSG","7030"]],
            AUTHORITY["EPSG","6326"]],
        PRIMEM["Greenwich",0],
        UNIT["degree",0.0174532925199433],
        AUTHORITY["EPSG","4326"]],
    PROJECTION["Transverse_Mercator"],
    PARAMETER["latitude_of_origin",0],
    PARAMETER["central_meridian",33],
    PARAMETER["scale_factor",0.9996],
    PARAMETER["false_easting",500000],
    PARAMETER["false_northing",10000000],
    UNIT["metre",1,
        AUTHORITY["EPSG","9001"]],
    AUTHORITY["EPSG","32736"]]

Here is the projection info from GRASS for my location:

+proj=utm
+south
+no_defs
+zone=36
+a=6378137
+rf=298.257223563
+towgs84=0.000,0.000,0.000
+to_meter=1

Without reprojecting the MODIS image, I can import it into GRASS even
though the projection systems don't match with:

GRASS 6.4.2 (kenya):~/PullDir/0302568977ukjJXB/001 > r.in.gdal
input=MOD112_2004_001.LST_Night_1km.tif output=foo.testing
Projection of input dataset and current location appear to match
 100%
r.in.gdal complete. Raster map <foo.testing> created.

version: GRASS 6.4.2
OS: MacOS X ML (10.8.2)

Regards,
Shaun

(sorry for any duplicates, I sent it to the wrong users list)

--------------------------
Shaun Langley
Doctoral Candidate
Department of Geography
Michigan State University
(562) 281-7847


On Thu, Mar 14, 2013 at 3:09 AM, Markus Neteler <neteler at osgeo.org> wrote:

> On Thu, Mar 14, 2013 at 2:57 AM, Shaun Langley <shaunlangley at gmail.com>
> wrote:
> > I'm wondering if I've stumbled on a bug…
> >
> > I'm working with a bunch of MODIS data that I've converted to UTM (Zone
> 36, WGS84) using the Modis Reprojection Tool.  Using gdal I can see that
> these maps have projections of EPSG:32636; however my GRASS location is
> defined with EPSG:32736.  When importing into grass with r.in.gdal, GRASS
> identifies the two projections as the same and allows me to proceed to
> import without error.  When displaying the maps though, it's obvious that
> the projections were wrong.  It too me a long time to figure this problem
> out and I'm just wondering if maybe it's a bug?
>
> Please post whch GRASS version on which OS you use and
> ideally also the command lines + messages to give better help.
>
> (We do similar things and did not meet such problems)
>
> Markus
>
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