I have uploaded a .DWG file of a cave system that will overlay DEMs. When I rectify the .DWG file it seems to be more stretched and not completely in line when compared to the original PDF file of the map. To rectify the image, I am taking coordinates from that PDF and using them to rectify the .DWG. I am just eyeballing it which is probably why it's not accurate. Is there a way to make it more accurate?