[GRASS-user] GeoTIFF, EPSG and GRASS

[Markus Neteler]

Hi,

I have tried with GRASS 7.0.svn:

On Thu, Aug 21, 2014 at 3:32 PM, Adrien ANDRÉ <adrien.andre at onf.fr> wrote:
...
> i use EPSG:2972 to reproject any new raster i'm lead to work with.

(http://epsg.io/2972)


> gdalinfo says:
>
> Coordinate System is:
> PROJCS["RGFG95 / UTM zone 22N",
>     GEOGCS["RGFG95",
>         DATUM["Reseau_Geodesique_Francais_Guyane_1995",
>             SPHEROID["GRS 1980",6378137,298.2572221010002,
>                 AUTHORITY["EPSG","7019"]],
>             TOWGS84[0,0,0,0,0,0,0],
>             AUTHORITY["EPSG","6624"]],
...
> The PROJCS has lost its AUTHORITY parameter.
> Would someone know why this happens? Is there a way to fix this?

grass70 -c epsg:2972 ~/grassdata/test1

GRASS 7.0.0svn (test1):~ > g.proj -w
PROJCS["UTM Zone 22, Northern Hemisphere",
    GEOGCS["grs80",
        DATUM["unknown",
            SPHEROID["Geodetic_Reference_System_1980",6378137,298.257222101],
            TOWGS84[2,2,-2,0,0,0,0]],
        PRIMEM["Greenwich",0],
        UNIT["degree",0.0174532925199433]],
    PROJECTION["Transverse_Mercator"],
    PARAMETER["latitude_of_origin",0],
    PARAMETER["central_meridian",-51],
    PARAMETER["scale_factor",0.9996],
    PARAMETER["false_easting",500000],
    PARAMETER["false_northing",0],
    UNIT["Meter",1]]

--> DATUM["unknown",

This happens when the datum is not understood by GRASS. One solution
in the past for similar (not yet sure if it *is* similar) was to
register the name, see:

http://trac.osgeo.org/grass/browser/grass/branches/releasebranch_7_0/lib/proj/convert.c#L732

On the other hand, the spelling seems to be the same. No idea...

Mhh, or are the CSV files included in lib/proj/ too old which we
copied in the past from GDAL, then stopped due to PROJ4 issues (which
are perhaps meanwhile solved)?

Markus