RWE, I don't use AutoCAD for anything. I used it from version 1 through 14, and wrote a surveying application for it in 1985, as well as other external programs to generate drawings from external data.
There are lots of sources of topographical data and maps, but I happen to have a need which LIDAR, USGS, UCDS, ESRI, etc do not address, so I am writing that enhancement for the same 3D modeling tool I use for machine design. That way, I don't have to jump around to 3 or 4 different CAD systems for different types of engineering.
You are using the same application on a 200 acre design project that is complex enough that no GIS/data resource has adequate contour data as you use in machine design?
Maybe you should hire a licensed land surveyor?
Curiosity has me intrigued at what makes your project so different that it cannot be accomplished with available information, but the additional information you need can be obtained with standard GPS.
But its the same curiosity I had when my cousin and I looked into a non-grounded electrical outlet, with butter knives in each hand.
