I'm fairly new to QGIS and Grass GIS, and learning the interface.
I have a CAD drawing that has no coordinate system assigned and needs to be georeferenced to NAD83 HARN Northern Colorado (feet).
I'm trying to use v.rectify to match known control points on the CAD drawing to their counterparts on a properly georeferenced vector map downloaded from the county website.
I keep getting the error:
Poorly placed control points. Can not generate the transformation equation.
So I assume I'm not going about setting these points properly.
I'm using the Digitize New Points function in GRASS to get the source coordinates at road intersections on the CAD drawing and in the County data, then putting them in notepad and using that for my input file.