On 11/8/05, Fischer, Andreas <[EMAIL PROTECTED]> wrote: > Dear list, > I'm using the ogr2ogr tool to convert PostGIS-data to MapInfo tab or > MIF-Files. The projection in the Database is EPSG:31463. The output-format > is supposed to be the same. > So I did use the following command. (I used -dsco "FORMAT=MIF", because the > conversion to MapInfo tab did not work well and I could take a look at > parameters in the files) > ogr2ogr -f "MapInfo File" test "PG:dbname=geodaten user=user host=host > port=port" -sql "Select * from test_tabelle" -dsco "FORMAT=MIF" -nln mi_test > -a_srs "EPSG:31463" > > The result is not the one I expected, because MapInfo does not show the > expected projektion (GK, DHDN Zone3). Instead it shows Longitude/Latitude, > even thought the Coordinates are o.k.. > So I took a look at the MIF-File and found the following line: > CoordSys Earth Projection 8, 104, "m", 9, 0, 1, 3500000, 0 Bounds(-30000000, > -15000000) (30000000, 15000000) > When I change this line to the following, the import of the MIF-File to > MapInfo worked fine. It has the right projection und the geometries of the > features are exact. This line is the same as in mapinfow.prj for this > projection and without Bounds-Clause the result was very precise > CoordSys Earth Projection 8, 1000, "m", 9, 0, 1, 3500000, 0 > > So does anyone know about the right parameters to give with ogr2ogr to get > the right line in the MIF-File? Or does anyone can help me otherwise to get > MapInfo-Files from PostGis-tables without manual work.
Andreas, The original problem is because the expansion of EPSG:31463 is not easily identified as being datum 1000 for mapinfo format. The name does not exactly match (it is called "DHDN_Potsdam_Rauenberg" in the mitab_spatialref.cpp file), and there is no corresponding TOWGS84 entry on the EPSG expansion. I believe the code falls back to using WGS84 (datum 104) when a datum cannot be identified. The workaround for you would be to run ogrinfo on a fixed mif file. Save the Well Known Text coordinate system description to a file, perhaps called 31463.prj, then issue the future ogr2ogr commands with the -a_srs 31463.prj commandline switch. The MITAB code should recognise that 31463.prj corresponds to datum 1000 and set the CoordSys properly. I appologise for these problems, but the area of coordinate system translation between systems is fraught with complexity and uncertainty. PS. I don't know why "CoordSys Earth Projection 8, 104, "m", 9, 0, 1, 3500000, 0" shows up in mapinfo as a geographic coordinate system. It should still be transverse mercator but with a datum of WGS84. Best regards, -- ---------------------------------------+-------------------------------------- I set the clouds in motion - turn up | Frank Warmerdam, [EMAIL PROTECTED] light and sound - activate the windows | http://pobox.com/~warmerdam and watch the world go round - Rush | Geospatial Programmer for Rent ------------------------ Yahoo! Groups Sponsor --------------------~--> Get Bzzzy! (real tools to help you find a job). Welcome to the Sweet Life. http://us.click.yahoo.com/A77XvD/vlQLAA/TtwFAA/dkFolB/TM --------------------------------------------------------------------~-> Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/mitab/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
