Lost GPS signal scare

Randy · Dec 20, 2016

I did the IMU calibration yesterday, took it out and flew it and about a minute into the flight it switched to ATTI mode and had lost satellites, it was very close to me, this lasted for about 30 seconds, I still had good control of it, landed it and it had a red "initializing IMU" for several minutes on the screen. I recalibrate the IMU again and flew it inside the hangar where it did fine, but haven't flown it outside since, scared to. I'm wondering if you switched it into sport mode would you still have total control even if it didn't have GPS?

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Mr Spock · Dec 20, 2016

Randy said:
I did the IMU calibration yesterday, took it out and flew it and about a minute into the flight it switched to ATTI mode and had lost satellites, it was very close to me, this lasted for about 30 seconds, I still had good control of it, landed it and it had a red "initializing IMU" for several minutes on the screen. I recalibrate the IMU again and flew it inside the hangar where it did fine, but haven't flown it outside since, scared to. I'm wondering if you switched it into sport mode would you still have total control even if it didn't have GPS?

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What Firmware are you on the Mavic Pro?

Mr Spock · Dec 20, 2016

Gumby said:
On a flight yesterday tracking with 17 satellites maximum signal.. 8 minutes into the flight get a "weak GPS" message on the controller and attempt to head back. Controller still shows 17 says but weak red GPS signal. I could not control the aircraft... drifted for over 2 minutes and ended up about 1,000 feet down wind.. I was able to see and rotate the camera and gimbal the whole time - but could not control the aircraft. RTH did not work. I could only watch as it drifted downwind.

Finally (after 2 or 3 long minutes) the GPS signal returned and RTH worked perfectly.

Now I'm a little gun shy to fly very far. Any idea what could have caused this? I was flying over my neighborhood at 375 feet and was about 2,200 away
When this happened. Signal was a solid 3 bars

Thoughts?

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What firmware are you on?

Randy · Dec 21, 2016

Not sure, I do an update whenever it tells me to, and it's not telling me to do one so I'm assuming it's the most recent. I watched a video that was posted here where someone else had the same "INITIALIZING IMU" right after landing in a wide open field all by itself, but they had lost all control. How can I determine what firmware I have?

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Mr Spock · Dec 21, 2016

Go to the DJIGO app top right hand corner on the ... 3 dots menu then scroll all tha way down and go into "about" and let us know what FW you are on. On the last FW 01.03.0000 in the release notes it was mentioned that and issue similar to what has been reported here is fixed.

SackboyDad · Dec 27, 2016

I had the same issue twice yesterday. Launched and after about two to three minutes of flying went to ATTI mode. Scared the crud out of me both times. Definitely drifting because it wasn't locked on to GPS.

The first time it happened, it came back in maybe 30-45 seconds. The second time it was much longer ...

This is my second mavic... first one was replaced by DJI for the jello issue. Now the jello is gone and this GPS freak-out has reared its ugly head.

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SteveCA · Dec 28, 2016

I had this happen to me a week and a half ago in Maui. I was flying along the coast and all of a sudden the controller vibrated and I heard it say Atti mode.unlike the other person, I had full control of the Mavic and had no problems flying it around and backed until it regained signal about two minutes later. I just chalked it up to poor GPS signal or high KPI index. When I got home I checked the KPI index and it was at three which should not have been a problem.

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Ludvig · Jan 1, 2017

Hi I just got my super Mavic after waiting for 2.5 months

I have only few flights under my belt so I am very new to this. I had already lost my GPS signals twice and it was scary as hell, lost control drifted in the wind and all that. All do I got my drone back twice by activating the go home as soon as I got my GPS back.
I thought about for some time and I was not happy and was losing my trust in the unit that I was waiting for such a long time :-(.
In my case i have figured it out

Looking at on the flight log and some use of brain power... the conclusion was interference. The Mavic went from 16-18 sat to zero in a second and almost at the same spot slightly different height behind my house.
I have a satellite dish for TV system and when the Mavic got in or close to the beam the GPS went out the window and all seemed lost

So if you were flying to close to the beam or to low altitude all the same you will or can loose the GPS !!!

I am not sure if it is the same in your case or there might be similar interference sources but i think it is worth think of.

Sorry for my English as I am from Norway and it's not my first language.

Brice LeCarre · Jan 1, 2017

Ludvig said:
Hi I just got my super Mavic after waiting for 2.5 months
I have only few flights under my belt so I am very new to this. I had already lost my GPS signals twice and it was scary as ****, lost control drifted in the wind and all that. All do I got my drone back twice by activating the go home as soon as I got my GPS back.
I thought about for some time and I was not happy and was losing my trust in the unit that I was waiting for such a long time :-(.
In my case i have figured it out Looking at on the flight log and some use of brain power... the conclusion was interference. The Mavic went from 16-18 sat to zero in a second and almost at the same spot slightly different height behind my house.
I have a satellite dish for TV system and when the Mavic got in or close to the beam the GPS went out the window and all seemed lost
So if you were flying to close to the beam or to low altitude all the same you will or can loose the GPS !!!

I am not sure if it is the same in your case or there might be similar interference sources but i think it is worth think of.

Sorry for my English as I am from Norway and it's not my first language.

Ludvig. Losing GPS does not mean it is an emergency. The drone will be fine. It is a little more difficult to fly precisely but by no mean a bad situation. In fact, it is a good idea to practice flying without the GPS system.

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SteveCA · Jan 2, 2017

It is a very good idea to learn to fly without GPS but unfortunately you cant turn it off and put it into ATTI mode. I am fortunate in that I flew RC helicopters first so it isn't a pants soiling moment when GPS is lost and the drone starts drifting. I don't know why DJI didn't make manual ATTI mode an option on the Mavic. That mode is available on my P4 but not on the Mavic

jetmo · Jan 14, 2017

I had the same problem with my mavic yesteryday. I lost my GPS signal twice! The scary part is that I also lost control over the mavic when it lost the GPS signal. I can't do RTH either. The mavic just flew away.. good thing that I got the signal back after about 30secs and only then I was able to land it safely.

SteveCA · Jan 15, 2017

I have learned to turn around and look at my homepoint from the air so that I can find my way back visually. It could be critical if you lose GPS and can't see your drone to guide it back.

harfordhawk · Jan 27, 2017

Just to add to this thread. I lost GPS today as well. The log says I had 16 sats the whole time. Same place I have flown many times with no problems.. In my case it happened when I switched from follow me mode. Unknown reasons, uploaded log to DJI and I hope they have some explanations..

vas67 · Jan 27, 2017

Anyone know if home lock feature would work in loss of GPS?
I've never lost GPS so I don't know if distance from controller to drone is still functional. If it is then maybe home lock could work?
I'm guessing you do loose distance function though.

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DirkGently · Feb 1, 2017

I just suffered the GPS loss issues described - did anyone get to the bottom of the issue?

Is it a hardware issue needing a RMA or just a firmware issue that DJI will hopefully sort out?

Mavic Magic · Feb 1, 2017

This also happen to me. Search for my post yesterday. Looking to see if others have had this issue and found your post.

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Will.i.am · Feb 1, 2017

Everyone may want to read up on how gps works and the causes of gps interference. GPS is not 100% reliable or accurate. Just don't expect it to be. The number of satellites doesn't always equate to the reliability or accuracy. Loss of gps lock is pretty much inevitable in civilian devices, so drone flyers need to recognize it and be able to react to atti mode. Another reason why you shouldn't fly beyond VLOS.

Do we know anything about the gps chipset that DJI uses in the Mavic? It might tell us something about sensitivity and expected accuracy and reliability.

Mavic Magic · Feb 1, 2017

Possibly your are correct but never happened to my P4. The redundancy is the number of satellites. I would think this is a hardware and/or firmware issue.

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harfordhawk · Feb 1, 2017

Yep. I have been flying rc planes with gps for many years. signal does not go from 15 sats to zero, in my experience. usually it may drop sats slowly. Now I have had specific gps units that never worked correctly, and they were flaky like 'some days seemed ok, then others couldn't get a lock'... I think this is hardware or firmware, and I am hoping its firmware!.. my experience with the mavic was when switching from the followme mode and that is what leads me to believe it is firmware.

DirkGently · Feb 1, 2017

Will.i.am said:
Everyone may want to read up on how gps works and the causes of gps interference. GPS is not 100% reliable or accurate. Just don't expect it to be. The number of satellites doesn't always equate to the reliability or accuracy. Loss of gps lock is pretty much inevitable in civilian devices, so drone flyers need to recognize it and be able to react to atti mode. Another reason why you shouldn't fly beyond VLOS.

Do we know anything about the gps chipset that DJI uses in the Mavic? It might tell us something about sensitivity and expected accuracy and reliability.

Nothing in this world is 100% accurate or reliable. But worst case scenario is the GPS tracking becomes less accurate - instead of accurate to +/-3 metres its +/- 10 metres.

It should not stop working completely unless blocked by a big object or very serious interference from say power lines.

I've used a GPS watch for over a decade and never had the problems with it the Mavic has. Sometimes its very accurate and sometimes less so - but once it has a fix it keeps it.

When the GPS was unavailable it meant the Mavic return to home didn't work - which you'd expect if the drone has no idea where it is.

So I think for now I'll keep my Mavic close until I can be sure the GPS was either a 1 off issue or at least fixed in firmware.