[Gdal-dev] OGR Georeference

[Rob McCulley]

Hi All,

I've got a bunch of .dgn files that are not georeferenced at all (i.e. the center of each file is (0,0)).  Each file corresponds exactly to one township, and I've got a shapefile with all of the townships.  In addition to the survey information, each file contains four points which are the four corners of the township.  The file name of each .dgn file corresponds with the township represented.

I've got a python script that opens the .dgn file, selects the appropriate township from the shapefile depending on the .dgn title, opens a shapefile to output to, and then I'm stumped.  Is it possible to use ogr to georeference this stuff?  I've looked at using a ogr::CoordinateTransform, but I can't figure out what to put as the source srs.

I know Arcview can do what I'm looking for, but it is a tedious manual process called Spatial Adjustment.  I've got 342 .dgn files to work through, so I'm looking to automate the process.

Thanks,
Rob McCulley
GIS Coordinator
County of Vermilion River No. 24
(780) 846-2244
www.vermilion-river.ab.ca