[Qgis-developer] OGRSpatialReference problem in QGIS

[Florian Hillen]

Hi Frank,

you're right. I use the OSGeo4W package under windows, so the files are in
C:\OSGeo4W\share\gdal and no environment variable is set.

After setting this, the GEOGCS seems to be recognized, but same problem
with datum and spheroid:

PROJCS["unnamed",
GEOGCS["DHDN",
DATUM["unknown",
SPHEROID["unretrievable - using WGS84",6378137,298.257223563]],
PRIMEM["Greenwich",0],
UNIT["degree",0.0174532925199433],
AUTHORITY["EPSG","4314"]],
PROJECTION["Transverse_Mercator"],
PARAMETER["latitude_of_origin",0],
PARAMETER["central_meridian",9],
PARAMETER["scale_factor",1],
PARAMETER["false_easting",3500000],
PARAMETER["false_northing",0],
UNIT["metre",1,
AUTHORITY["EPSG","9001"]]]

Do I have to set any other variable or something to fix that?

I will file a ticket by quoting you, thanks for your help so far!

Florian




> Florian Hillen wrote:
>> Hi Frank,
>>
>> thanks for the fast answer.
>> (projectSelector->selectedProj4String()).toUtf8() delivers the following
>> proj.4 string:
>>
>> +proj=tmerc +lat_0=0 +lon_0=9 +k=1 +x_0=3500000 +y_0=0 +ellps=bessel
>> +datum=potsdam +units=m +no_defs
>
> Florian,
>
> This proj.4 string works fine for me producing:
>
> PROJCS["unnamed",
>      GEOGCS["DHDN",
>          DATUM["Deutsches_Hauptdreiecksnetz",
>              SPHEROID["Bessel 1841",6377397.155,299.1528128,
>                  AUTHORITY["EPSG","7004"]],
>              TOWGS84[606,23,413,0,0,0,0],
>              AUTHORITY["EPSG","6314"]],
>          PRIMEM["Greenwich",0,
>              AUTHORITY["EPSG","8901"]],
>          UNIT["degree",0.01745329251994328,
>              AUTHORITY["EPSG","9122"]],
>          AUTHORITY["EPSG","4314"]],
>      PROJECTION["Transverse_Mercator"],
>      PARAMETER["latitude_of_origin",0],
>      PARAMETER["central_meridian",9],
>      PARAMETER["scale_factor",1],
>      PARAMETER["false_easting",3500000],
>      PARAMETER["false_northing",0],
>      UNIT["Meter",1]]
>
> I see this code in importFromProj4() for "datum=potsdam":
>
>      else if( EQUAL(pszValue,"potsdam") )
>      {
>          OGRSpatialReference oGCS;
>          oGCS.importFromEPSG( 4314 );
>          CopyGeogCSFrom( &oGCS );
>          bFullyDefined = TRUE;
>      }
>
> This leads me to suspect that the EPSG .csv files are not being found.
> These
> have the names gcs.csv and pcs.csv, are distributed as part of GDAL and
> are
> normally found somewhere like /usr/local/share/gdal/.  When in an unusual
> location you can use the GDAL_DATA environment variable to point to the
> directory holding them.
>
> This import code should really have some error checking to propogate a
> failure
> in importFromEPSG() back to the importFromProj4() caller.  If you would
> file
> a GDAL ticket on this issue, I'll have someone work on improving the error
> handling.  But the core solution is to ensure the support files are
> available
> and findable.
>
> Best regards,
> --
> ---------------------------------------+--------------------------------------
> I set the clouds in motion - turn up   | Frank Warmerdam,
> warmerdam at pobox.com
> light and sound - activate the windows | http://pobox.com/~warmerdam
> and watch the world go round - Rush    | Geospatial Programmer for Rent
>
>