So went out with some egg heads, they where telling me at the blackhat convention there was a guy who made a device that when the beam hits the drone it jams the gps signal and the drone litterly   falls out of the sky.we went out to test the this theory , it works the drone will fall but we tried it again this time with multi flight on and when I got the alert about GPS i switch ot to non gps and the drone recovered. From what I was told some law agencies are useing the drones to keep eyes on people of intrest and this is what they are using to take the drones down.  This might be the problem yall are facing in the bigger cities.  BUT by law (told to me by a aircraft pilot) it is against the law to take down any aircraft civilian or not... also illegal to jam gps signals unless you are part of law enforcement or millitary.... But from some of the posts I have read this might be what's happening. But I am not smart like these guys are.

Yeah i know how to build such device and yes it is possible, as in if we can do it then it's already being used by big brother.

the method is called GPS spoofing. they override the constant/weak signal from the orbiting satellites with a stranger ground based unit. theres another platform being developed that useses high frequency soundwaves to muck up the gyroscope. both systems are not going to be in the hands of average joe blow anytime soon

If you blast the 2.4ghz frequency range you will probably block the transmission between remote and quad. You will also disrupt everything else in that frequency range including Wifi. You will need a pretty strong transmitter or to be aiming at the flying quad all the time. If you could hijack the actual channel and send bad signals you could probably make it crash.  
If you blast it wiht 2.4Ghz transmission it will probably just go into non GPS mode. I don't know how the drone will react. It's up to the code written to determine the behavior in such situation.

The first thing that popped into my head was "What?!?  You're letting some guy test this drone killer out or YOUR Phantom?!?"
(but hey, if it was his, fly it like a rented mule!)

zoti Posted at 2015-10-11 23:44
If you blast the 2.4ghz frequency range you will probably block the transmission between remote and  ...

Blasting 2.4ghz jamming would just make the phantom go home, on the other hand blasting 1.2ghz and 1.5ghz and 1.6ghz you would jam GPS reception. So technically the phantom would be screwed if you jam 2.4ghz and 1.5ghz at the same time.

The more disruptive approach is to broadcast wrong coordinates to the phantom so the pilot will think it is acting up, so he switches to attitude, then you jam 2.4ghz and he looses communication, then you keep spoofing the location till it crashes.

Still it is quite a design flaw that the drone would crash in this condition. Dji wouldn't it be better that in case of losing the GPS signal the drone would return to the home point? There is no logical reason why a drone would have to crash when the signal is lost.. It knows where the homepoint is or it could at least just land itself right? The altitude isn't 'reset' right so why would it crash?

DeDroneMeneer Posted at 2015-10-12 03:16
Still it is quite a design flaw that the drone would crash in this condition. Dji wouldn't it be bet ...

From what I've read the aircraft needs GPS to find its way home.  Without GPS it will just land in place.  I do agree that the firmware needs to be changed so that if the compass or GPS malfunctions that it should automatically go to ATTI mode instead of flying back to  China or wherever flyaways go.  If it went to ATTI it should hover in place unless there is wind which would still blow it away until the battery went dead and than land in place.  Better than flying off and crashing.

DeDroneMeneer Posted at 2015-10-12 09:16
Still it is quite a design flaw that the drone would crash in this condition. Dji wouldn't it be bet ...

Yes. But if the GPS gets screwed up it cant return to its "home" point since it doesnt find the correct one...

Most of you aren't old enough to remember that when GPS became commercially available, that the US government was concerned  that it could be used for targeting against US forces.

They (the government) induced a random deviation into the signal so that the accuracy was +/_ 50 yards or so.  The Russian GLONASS GPS was devised so that they also had a GPS signal for use.

When the government stopped supporting the Loran C signal used for marine navigation, they were forced to remove the deviation from the GPS signal.

Okay I understand - but what I meant was that there should be an "failsafe" homepoint GPS stored - which could be triggered if it was to be jammed..

(Or just hovering instead of crashing - I don't understand why a drone would crash when the GPS is jammed) I understand it needs it for navigation - but a car won't crash when the GPS is jammed right

DeDroneMeneer Posted at 2015-10-12 09:33
(Or just hovering instead of crashing - I don't understand why a drone would crash when the GPS is j ...

Your car isn't being navigated via GPS. If you were driving GPS only, totally blind to the rest of the world, you'd crash.

The Google cars use GPS, radar, sonar, and cameras to keep it in lane. If you've ever seen the computer system inside of one, you'd get a better understanding of the complexity involved.

The Phantom is blind without the GPS. It doesn't know where HOME is. It doesn't know where IT is without GPS. Your ability to switch to ATTI mode is like taking the controls on the self driving car.

DeDroneMeneer Posted at 2015-10-12 21:31
Okay I understand - but what I meant was that there should be an "failsafe" homepoint GPS stored - w ...

I think you've missed how GPS works...

If you imagine the GPS signals from many satellites painting a 'grid' in the sky that your GPS picks up..

Once the GPS signal is blocked the grid is gone..  Having stored locations on the grid is useless as the Phantom would not no where to go to find 'home' or any other location.

That is why fly-aways can happen during high solar activity as the GPS signal is distorted / blocked by the noise from the solar flares and the "grid" is distorted or not longer there...   

at a wild guess such devices would be highly illegal to sell or own.
GPS is a military system and you'd be jamming the military in that little area. I think the authorities in any country would very much like to throw the book at anyone found with that kind of thing.
They don't even like cellphone jammers, after all.

I would have thought that if there is no valid GPS, then the P3 would simply land where it is. Not fly away, nor try to find a non-existent home position.

gil Posted at 2015-10-11 22:47
The first thing that popped into my head was "What?!?  You're letting some guy test this drone kille ...

it was in a controlled setting first time drone was just 6 inches off the ground. The reason I was ok with the testing is because it was controlled better to learn what can be done and how to recover in a controlled setting instead of shooting video in the city 200-400ft up and all a sudden it drops out of the sky. The guy is in Cyber Security and is a good friend of a life long friend.. Its not being retarded its retarded to hear rumors and then have a chance to see how it works and how you can recover and Not take the chance to learn.... just my 2 cents.