I have some low-quality vector data and I'm trying to align some higher-quality raster images with it so that I can improve the vectors. Unfortunately the rasters have no control points or coordinates, so I have to align the images by matching up two identifiable points that exist in both the raster and the vector:
In my 3D software, I can align to these two points without distortion simply by locking the aspect ratio, to get this result:
But using the Qgis Georeferencer with the same points, I get a distorted result (note that the raster is now considerably less wide left-to-right than the vector):
I tried different transformation types in the georeferencer and none of them gave the desired result. I kept the CRS set to the same one as the project (WGS84).
How can I align the raster in QGIS with a simple rotate and scale, without altering the aspect ratio?