On 11-05-06 09:48 AM, Luca Sigfrido Percich wrote:
I use the '-s_srs' command and when I overlay the shapefile over a
map,the adjustment isn´t very good with the map, so I must make a
geographic transformation. I get that transformation thanks to
'ProjectionUtility' (ArcView). Its name is Geocentric[9603],
ED_1950_TO_WGS_1984_13, POSC Code:8045.
I need to make this transformation automatically. How can I make this
transformation using 'ogr2ogr'? Is it possible?
I'm just guessing 'cause I've never tried this. Check if ProjectUtility
writes a .prj file; it should contain a WKT definition of the resulting
dataset SRS. According to ogr2ogr doc, this WKT (or the name of the file
containing it) can be passed to -t_srs or -a_srs.
Sig / Mario,
ESRI .prj files do not normally have the details of the datum shift
parameters in them. I see the "stock" ED50 transformation in EPSG is
TOWGS84[-130,29,364,0,0,0,0] so hopefully you could do something like:
ogr2ogr -s_srs "+proj=latlong +ellpse=clrk80 towgs84=-130,29,364,0,0,0,0" \
-t_srs "+proj=latlong +datum=WGS84" \
out.shp in.shp
or something similar. This is assuming the coordinates are geographic
(lat/long), not projected. If they are projected you will need a more
complex source and destination coordinate system description.
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
_______________________________________________
gdal-dev mailing list
[email protected]
http://lists.osgeo.org/mailman/listinfo/gdal-dev
