Edits to DB using DEM

Submenu on "EDIT" button on database table form.   You must enable edits before this option is available.

You must consider the scale of the DEM to know if the operation is appropriate.  For lidar, you have to decide if you want a DTM/DSM.

• For point DBs, it uses the point's location.
• For line or area shapefiles, it uses the centroid if that is present, or the center of the bounding box.  You need to decide if the size of the record, and the variation in the DEM at that scale, make the results useful.

Options

• Add interpolated elevation from DEM: put elevation for each lat/long point in the database, placing it in field "ELEVATION"
• Add nearest elevation from DEM:
• Add nearest integer elevation from DEM: required for things like landcover when you want to filter the DB by category
• Add slope/aspect from DEM: put slope in percent for each lat/long point in the database, placing it in field "SLOPE_PC"
• Add elevation difference from DEM: 
• Add elevation from DEM series
• Find records on DEM
• Pick grid and add nearest value
• Place values in DEM
• Add EGM fields: EGM96, EGM2006, and the difference between them.
• Compute intervisibility from point: enter a location, and the height of the observer.  The program will compute the aziumuth and pitch to each record in the database, and show them as either visible for masked by intermediate terrain.

Last revision 8/21/2021