I suspect that for most hobiest use of MAVLink, the altitude parameter for waypoints is treated as relative to the launch altitude; Perhaps even when the GLOBAL (0) frame is specified. However, Droidplanner is specifying MAV_FRAME.MAV_FRAME_GLOBAL for any waypoints it creates. Should MAV_FRAME.MAV_FRAME_GLOBAL_RELATIVE_ALT be used instead so we say what we most-likely mean?
I have been using MAV_FRAME.MAV_FRAME_GLOBAL_RELATIVE_ALT in my testing of the AR.Drone, though I suspect it treats all waypoints as relative altitude, even those marked as global. I didn’t include this in my branch yet because I’m not sure what other MAVs might be doing.
Is this change safe for other users of Droidplanner? If not, should and option be provided to choose the frame? Or should it be configurable for each waypoint like QGroundControl does?
–Brad