I (correctly) georeferenced a JPEG to an existing shapefile that was in the correct coordinate system.

I then proceeded to create line feature classes by manually tracing some of the features (roads) from the JPEG.

The mistake: When creating the line feature classes, I used the wrong coordinate system for the feature datasets, and so the line feature classes are all in the wrong coordinate system.

The result is that the feature classes are appearing in the correct location (because I manually traced them over the georeferenced JPG) but are in the incorrect coordinate system. Essentially I need a way to update the coordinate system to the correct projection without changing the location of the lines.

  • 2
    What software are you using?
    – mkennedy
    Mar 17, 2016 at 16:39

1 Answer 1


I think you can just redefine the coordinate system. In ArcGIS, it would be the data's property page or the Define Projection Tool.

You probably should try removing any coordinate system ("clear" it) and see if the lines features still line up. If they do, good to go.

If they don't line up, the software may have projected the digitized coordinates (in the JPG's coordinate system) into the coordinate system of the feature class. In that case, you would need to Project the feature classes into the coordinate system you want. The reason that they still line up is that ArcMap or the "viewer" you're using is projecting them on-the-fly to the display's coordinate system.

  • Thanks for your response! I am using arcmap 10.3. Unfortunately just changing the projection in the data's Properties shifted the location of the data, and define projection is giving me the same results. What does seem to be working is creating a new feature dataset with the correct projection, and importing the old feature classes directly into the new feature dataset. It is somewhat cumbersome, but I am not working with a vast amount of data and the results seem to be OK. Thanks again for your help.
    – MMGIS
    Mar 17, 2016 at 16:56

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.