Geographic Information Systems Stack Exchange is a question and answer site for cartographers, geographers and GIS professionals. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have a DEM that was exported from AutoCAD civil 3D 2013 but it's in the wrong projection. I'm using an area specific projection that was not provided as an option in CAD DEM export dialog box. I choose an other projection to finish the export and now I want to associate the proper projection to the DEM. Is there a way to redefine the projection of the DEM in ArcGIS 10.1 to the proper one?

share|improve this question
Can you choose a nonprojected coordinate system to export your CAD Data like WGS1984 and then project to your appropriate system once you import into ArcGIS? The tool in Arc to project is Project (Data Management). You will first need to Define(Data Management) using the coordinate system you exported out of AutoCAD if Arc reads your coordinate system as "Undefined" – Conor Aug 22 '13 at 19:10
Have you looked at Define Projection? I think this is the tool you need. – PolyGeo Aug 23 '13 at 1:42
@Conor It appears that AutoCAD only supplies common projected coordinate systems when exporting a TIN to DEM – Sarah Aug 23 '13 at 16:08
@PROBERT maybe I am looking in the wrong spot but I don't see a button to clear the coordinate system – Sarah Aug 23 '13 at 16:13
@PROBERT Thanks, I found the clear button. I never knew that it existed. Unfortunately it looks like it only clears the coordinate system assigned to the data frame not to the data (dem) itself. – Sarah Aug 23 '13 at 19:34

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Browse other questions tagged or ask your own question.