From what I understand, the dropdown (Relative/Absolute/Terrain) determines what the “Alt” column means. Also, when you export waypoints using the “Save WP File” button, the value of the dropdown determines the altitude frame of reference (third column).
However, checking “Verify Height” has no effect on the exported waypoint file. Does that also mean that checking “Verify Height” has no effect on how waypoints are interpreted by the autopilot?
If so, then “Verify Height” is only for UI point-and-click functionality. However, it still doesn’t make sense in the following scenario:
- Select “Terrain” mode
- Set “Default Alt” to 100
- Check “Verify Height”
- Point and click on the map
- “Verify Height” should have no effect on “Alt” values (they should be 100 everywhere), because they already mean “above terrain”. I mean, since I’m in “Terrain” mode, “Alt” will already be adjusted by the autopilot to follow the surface, I don’t need mission planner to add an offset relative to home.
- “Verify Height” modifies altitude on clicked points relative to home altitude as if I was in “Relative” mode.
So to sum up, is “Verify Height” checkbox just for point-and-click UI, or does it have an effect on how the autopilot treats “Alt” column and, as a result, to the content of exported waypoint file? If the former is the case, then its behaviour in terrain mode is odd and counter-intuitive.