[gdal-dev] EPSG code not recognized from GeoTiff written by GDAL

[Even Rouault]

On Friday 27 May 2016 11:46:14 Jukka Rahkonen wrote:
> Blumentrath, Stefan <Stefan.Blumentrath <at> nina.no> writes:
> > Hei,
> >  
> > We are facing issues with GeoTiffs that were written by GDAL, after
> 
> importing them to GeoServer or opening in Desktop GIS.
> 
> > On file was produced in GRASS and exported using r.out.gdal (GDAL 2.1dev),
> 
> the other file in R, using rgdal (GDAL2.0.x) with EPSG code 25832.
> 
> > The rasters seem to miss the AUTHORITY parameter...
> >  
> > QGIS for example detects EPSG 3044 (which is technically identical), and
> 
> GeoServer considers the CRS as invalid (because of this:
> 
> http://docs.geonode.org/en/master/tutorials/advanced/geonode_production/adv_
> gsconfig/crs_handling.html).
> >  
> > Did anyone else experience the same?
> 
> Hi,
> 
> From my GDAL 2.1-dev
> 
> gdalsrsinfo epsg:25832
> 
> PROJ.4 : '+proj=utm +zone=32 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m
> +no_de fs '
> 
> OGC WKT :
> PROJCS["ETRS89 / UTM zone 32N",
>     GEOGCS["ETRS89",
>         DATUM["European_Terrestrial_Reference_System_1989",
>             SPHEROID["GRS 1980",6378137,298.257222101,
>                 AUTHORITY["EPSG","7019"]],
>             TOWGS84[0,0,0,0,0,0,0],
>             AUTHORITY["EPSG","6258"]],
>         PRIMEM["Greenwich",0,
>             AUTHORITY["EPSG","8901"]],
>         UNIT["degree",0.0174532925199433,
>             AUTHORITY["EPSG","9122"]],
>         AUTHORITY["EPSG","4258"]],
>     PROJECTION["Transverse_Mercator"],
>     PARAMETER["latitude_of_origin",0],
>     PARAMETER["central_meridian",9],
>     PARAMETER["scale_factor",0.9996],
>     PARAMETER["false_easting",500000],
>     PARAMETER["false_northing",0],
>     UNIT["metre",1,
>         AUTHORITY["EPSG","9001"]],
>     AXIS["Easting",EAST],
>     AXIS["Northing",NORTH],
>     AUTHORITY["EPSG","25832"]]
> 
> 
> Do you get the same result? If you do I wonder why AUTHORITY is not written
> into GeoTIFF.


For diagnosing, what is interesting is the output of the listgeo utility that 
comes with libgeotiff.
Theoretically the EPSG code should be preserved in the geotiff keys if it is 
available in the source raster (gdal_translate use case), or if set with the 
SetProjection() API. I'm not sure about GRASS or R but perhaps they build the 
GDAL SRS object from a proj.4 string, in which case the EPSG code will be 
missing.


> 
> -Jukka Rahkonen-
> 
> >  
> > Kind regards,
> > Stefan
> 
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