I am trying to delete or classify "non-ground" areas in my point cloud. Basically need to delete any points from vehicles, buildings, construction materials etc ie. I want a DTM not a DEM.
Usually I run the point cloud "classify ground" tool to get rid of most of the obvious points, but it still leaves a lot of points which screw up the resultant mesh or DEM output.
So then I go through and select areas with polygons and either delete or classify as "man-made object " etc but find this still leaves residual points that don't get deleted or re-classified so I need to perform this procedure 2 or sometimes 3 times on each area.
Am I doing something wrong or is there a more efficient way to get rid of these unwanted points and give me a quicker ground surface?
thanks