It does not appear that ArduPilot supports a method for offboard position determination. I know mavlink has some commands for vision derived positions.
If I wanted to add this capability, any tips on where I should start? I was thinking about modeling it after the AP_GPS_PX4, and just creating AP_GPS_MAVLINK or something similar. Thoughts?
My biggest concern is that I want to make sure that the yaw commands coming from the mavlink are used, even when stationary. I do not have an external mag, and I am concerned about interference.