GPS failsafe options/extensions


I like flying Ardupilot-driven planes in mountains. It is inevitable that this means no permanent RC/video link, for example when flying in valleys or around mountains. There is an option of using a lidar for checking if GPS is correct by comparing to the elevation map on a companion computer, but this does not provide (at least in an easy way) the alternative navigation method.

So we are left with trying to fly in the direction of the home/operator location, and not crashing into terrain. And I have some questions/comments about this.

Is there any way (ArduPilot parameter) for increasing the altitude when the GPS signal is lost? I think the following options could be possible:

-VTOL for increasing altitude if available
-HTOL ascent with programmed glide angle
-HTOL in circles, with programmed radius and direction (assuming that the flight path will be written in the way that slopes are always to the right, and we want to circle anticlockwise)

Is this possible?

The next issue is the AFS_WP_GPS_LOSS. I can’t understand how is the drone navigating towards it? By compass heading? I suggest some permanent setting (say -2) for home location.

And the final issue: would it be possible to use the RSSI for the RC link for flying close to the home location? The airplane would fly in the direction of maximal RSSI, trying to develop some pattern for that? (of course there can be signal reflections and it probably never would be very precise, but hopefully enough to get into the RC signal range). Has this been considered?

Just some ideas for making ArduPilot even better and more reliable in potentially difficult environments :slight_smile: