No support for EPSG:31467 (Datum = Deutsches_Hauptdreiecksnetz) in MITAB

[tagru]

I tried to convert a dxf File to a Tab file and assigned the right EPSG-Code (​http://spatialreference.org/ref/epsg/31467/).

ogr2ogr -f "Mapinfo File" -a_srs "EPSG:31467" test.t
ab test.dxf

Applying

gdalsrsinfo test.tab

returns

PROJ.4 : '+proj=tmerc +lat_0=0 +lon_0=9 +k=1 +x_0=3500000 +y_0=0 +ellps=WGS84 +t
owgs84=0,0,0,-0,-0,-0,0 +units=m +no_defs '

OGC WKT :
PROJCS["unnamed",
    GEOGCS["unnamed",
        DATUM["WGS_1984",
            SPHEROID["WGS 84",6378137,298.257223563],
            TOWGS84[0,0,0,-0,-0,-0,0]],
        PRIMEM["Greenwich",0],
        UNIT["degree",0.0174532925199433]],
    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",1.0]]

So the a_srs parameter has no effect. I also tried to assign a source SRS (s_srs) but the result was no projection at all.

ogr2ogr -f "Mapinfo File" -s_srs "EPSG:31467" test.t
ab test.dxf

PROJ.4 : ''

OGC WKT :
LOCAL_CS["Nonearth",
    UNIT["Meter",1.0]]

Unfortunatly I can not provide an Example File.

[Even Rouault]

Well, -a_srs *does* have an effect. It is just that the conversion to MapInfo is not perfect, the main difference being the loss of Bessel 1841, that is considered as WGS84.

(It is expected that -s_srs alone has no effect. It must be in combination with -t_srs)

[tagru]

Well, ok but how does it happen that it assigns the wrong ellipsoid? I thought that maybe it just does a fallback to the default WGS84 option, because for some reason it does not recognize the projection.

(adding -s_srs and -t_srs produces the same result as -a_srs)

[tagru]

After running in an similiar problem and finding this http://trac.osgeo.org/gdal/ticket/481 I found a workaround. The Problem seems to be that the EPSG-Codes are not maintained properly for the MITAB projection definitions.

So I created a TAB-File through MAPINFO with the desired projection, extracted the WKT-Defintion from this TAB-File through gdalsrsinfo and used the created Definition with ogr2ogr. Result was a File with the proper Projection and not the fallback to WGS84.

Don't know if it can be fixed but this Workaround helps.

[Jukka Rahkonen]

Feels like something should be done in mitab code for a proper fix.

[Even Rouault]

This ticket has been automatically closed because Trac is no longer used for GDAL bug tracking, since the project has migrated to GitHub. If you believe this ticket is still valid, you may file it to ​https://github.com/OSGeo/gdal/issues if it is not already reported there.