06-20-2019 12:41 AM
I am a new user to ERDAS and am using an older version (2014). I am working with ATCOR3 to perform atmospheric and topographical correction to Landsat 8 images. I am running into some trouble when generating the slope, aspect, skyview, and shadow files from my DEM. I keep getting a message saying "Units are not of same type". From my understanding this is saying the my DEM and stacked (Bands 2-7) files do not have the same units. My DEM pixel size for X is 0.00027 and Y is 0.00027. My stacked file is 30, 30. So I resampled my DEM file to 30, 30. I then click on the ATCOR3 tool and then get a message "Resample DEM to same pixelsize in x and y direction". I recheck my pixel size for the DEM and stacked file, they are both set to 30, 30. Not sure what else to do????
Solved! Go to Solution.
06-20-2019 06:35 AM
Have you checked your original DEM to make sure it has a vertical datum defined, with appropriate units for the height information (which will be different from the dd you appear to be using for the horizontal pixel dimensions)?
06-20-2019 06:25 PM
My supervisor said they think it is in meters. I am unsure how to check that. I opened it up into ArcMap and the only information about datums under Layer Properties --> Source is Datum: D_WGS_1984. Is there somewhere else I can find this data? The DEM is from SRTM. From my understanding, SRTM is in meters.
06-20-2019 06:50 PM
I belive I have fixed the problem. Something was going on with my exported projected WGS dem. I used the projected file from my supervisor and everything is running smoothly so far.
06-21-2019 05:57 AM
Glad to hear you sorted it out.
For future reference the Elevation Info for a DEM can be reviewed and/or defined using the View/Edit Image Metadata dialog.
Home tab > Information group > Metadata pull-down > View/Edit Image Metadata