GPS failure-what happens to Radar display?

[dannyz]

That's the conclusion I came to during the indoor experiment I carried out above. There was no distance information but as you say the heading and relative position could still be used to bring the aircraft back. But I guess you would need to have a GPS failure to be sure.
I suppose the fact that despite asking for information from anyone who has had a GPS failure to fill in the facts, no one has has come forward. So that must support the argument that a total GPS failure is remote. That, at least, is a pleasing conclusion.

So, should work to cover the top of the AC with heavy aluminum foil, simulating loss of GPS, fly it, see if you can fly by radar? Will that answer the original question?

 

[davideo0]

So, should work to cover the top of the AC with heavy aluminum foil, simulating loss of GPS, fly it, see if you can fly by radar? Will that answer the original question?

I believe it would, Dannyz. But with my DIY skills, I'm not sure I'm the man to foul up my pristine P4P with glue or whatever, or risk the foil becoming detached and fouling the props. That's why I was looking for pilots with appropriate experience. Or maybe someone with a less expensive phantom would be prepared to take the risk ;o)

 

[Russ43Phantom]

If you lose your GPS and the radar display does not work, you should switch to HOME LOCK MODE and pull your right control toward you. It will return regardless of the drone's YAW.

 

[With The Birds]

If you lose your GPS and the radar display does not work, you should switch to HOME LOCK MODE and pull your right control toward you. It will return regardless of the drone's YAW.

What are you basing this advice on. The heading depicted by the radar is derived from the compass, It still works. How do you propose home lock may provide for your AC returning home with no GPS? It would not seem possible in the absence of available GPS data (current position referenced to home point). Have you managed to do this?

 

[KevMo Photog]

What are you basing this advice on. The heading depicted by the radar is derived from the compass, It still works. How do you propose home lock may provide for your AC returning home with no GPS? It would not seem possible in the absence of available GPS data (current position referenced to home point). Have you managed to do this?

Following on this one! Not sure how this could work either!

 

[Russ43Phantom]

Following on this one! Not sure how this could work either!

Good catch. But ... my thought is that if the last recorded drone position and the originally recorded Home Point were on record in the flight data, the Phantom might be able to calculate a compass heading to get it back close enough to be heard and then seen. The same logic that would drive RTH (if it exists) when there is a GPS failure and only a calculated compass heading can be determined.

 

[DanMan32]

I don't think RTH would work without GPS. In ATTI mode GPS is not being used for normal flight, but it will still use GPS for telemetry and RTH. If you lose GPS completely, AC will have little to go on. I don't think it can give you distance.

 

[Russ43Phantom]

I don't think RTH would work without GPS. In ATTI mode GPS is not being used for normal flight, but it will still use GPS for telemetry and RTH. If you lose GPS completely, AC will have little to go on. I don't think it can give you distance.

Agree no distance would be possibe without GPS. If a compass reading were calculated, and if it is set to be used when there is no GPS, you would have to hope the calculated compass heading would get the drone close enough to be heard and then seen. This concept IS hypothetical until tested. I don't know what DJI actually has to cover a lost GPS signal.