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dpitman said:Hi Folks,
I don't yet have GM.
In GM, how do you examine the coordinates of check shots to compare them to surveyed values?
Since you're using the term "GCPs", I'm assuming that you're a drone user. The way I compare checkshots to my drone-derived DSM/DTM is:
1: Import GCPs
2. Use calculate/copy attributes tool to copy "ELEVATION" attribute to a new attribute called "Observed"
3. Turn on DSM/DTM layer if it's not already on
4. Select all checkpoints and right-click--->analysis---> apply elevations to features
5. Use calculate/copy attributes tool to copy "ELEVATION" attribute to a new attribute called "Predicted"
6. Use calculate/copy attributes tool with the formula OBSERVED - PREDICTED, and write it to an attribute called "Delta"
7. change display labels to "Delta" attribute. Export as CSV to calc RMSE, if needed.
You can also convert the DSM/DTM to a point cloud (or "Create points at elevation grid cell centers") and use the lidar QA/QC tool. The lidar tool will sample nearby points. The workflow above will sample a single cell/pixel at the same XY coordinates as your control point.