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[MPP] Compass Error, Exit P-GPS Mode (YAW Error)
419 32 4-20 14:55
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Nordium
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Hello all,
I was flying my Mavic Pro Platinum around in my neighborhood earlier before I experienced a very scary event. I had 3 completely successful flights before this occurred - I was flying completely fine for around 30 seconds (see flight log) on my 4th flight when I got a message "Compass Error, Exit P-GPS Mode" and suddently the aircraft started to drift to the left very quickly (windless day - 0-4 mph gusts). I also received multiple "YAW Error", "Compass Heading Error", and "Compass Redudancy Switch" messages.
I've never had any crashes or hard landings with this drone - it's only 6 months old. I've attached my PhantomHelp flight log of the flight where the event occured below.

Flight Log: https://www.phantomhelp.com/LogViewer/TYZZPS7LOASPOHRC97G3/

Any help or advice/analysis would be appreciated - I have to fly as soon as tomorrow to inspect a roof. I'm hoping an IMU and Compass recalibration will do the trick.


Thanks!
4-20 14:55
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hallmark007
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This is not completely unusual with Mavic Pro or platinum, although you had some flights that were ok this log looks familiar and I will explain below.

It looks like you took off close to or on concrete footpath and my guess is you picked up some magnetic interference, I will explain below what happens in this situation, regarding calibration it’s not necessary but it won’t do any harm if done correctly.


The best way I can explain this is. If you put your Aircraft on the ground in normal circumstances, start it up, then lift it up and turn it 90 degrees to the right both your compass heading and IMU will both move together 90 degrees and no problems.
If you put your Aircraft on the ground and there is magnetic interference only the heading of your compass will change, your aircraft will still take off. But when it clears magnetic interference compass will then move to correct heading which you would think was great. But No, what happens is IMU is then conflicted and confused because of this sudden movement by compass, so you receive IMU exceptional heading warning, your aircraft cannot deal with data conflict so decides to switch to Atti mode dropping gps in favour of compass simply because aircraft can fly without gps but not compass.

It looks like your craft corrected it’s self and all ended well, this is good to see , good luck and fly safe.
4-20 15:38
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Goldchucker
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Hi hallmark007

Quote:
"The best way I can explain this is. If you put your Aircraft on the ground in normal circumstances, start it up, then lift it up and turn it 90 degrees to the right both your compass heading and IMU will both move together 90 degrees and no problems.:


Would it be a good idea to preform a 90 right turn each time the drone lifts off?  
Couldn't hurt, Right?

Thank you,
Chuck
  
4-20 19:21
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HedgeTrimmer
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Based on Flight Data as decoded, there is no indication of compass problem prior to and during take off in either CSV or extended CSV data files.

Compass Error occurs at 27.8-seconds and altitude of 194.9-feet.
Based on GPS coordiantes and Google maps, it does look like you took off from sidewalk.  
The Yaw errors start at 26.6-seconds.

Did you get any kind of Compass warning or Magnetic Interference warning prior to or at time off take off?
Did GO-4 app show "Green" as in good to go?

When was MPp's compasses last succesfully calibrated and where?
For future info, do you know what levels of magnetic field interference each compass showed at time of calibration?  What about now in an areas well away from any sources of magnetic field interference?


If you know the exact spot of takeoff, you can check take off spot using either: Mavic Pro P's compasses or with one of free (or nearly free) Magentic Field Strength Apps on a SmartDevice for source(s) of magnetic interference.  Sources, such as rebar in concrete, buried metal gas or water line, or electric power, cable, or telephone lines.
Added: There may not be any steel rebar in sidewalk, instead metal mesh.  Or no metal at all.


If you check with Mavic Pro P via GO-4 App, you will need to move drone around and even rotate drone through 180-degrees.  From testing I have done, the Mavic Pro P has to be very close to buried metal (like rebar or steel pipe)  and turned nearly parrellel with rebar or steel pipe to cause both compasses to have problems at same time.

Smartdevice running a Magnetic Field Strength App tends to be less picky about direction aimed, in part due to how data is gathered, and most Smartdevice only have one compass.

Glad you were able to keep drone flying and land it without damage

4-20 21:13
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HedgeTrimmer
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I'm hoping an IMU and Compass recalibration will do the trick.

For purpose of seeing what might have caused Compass Error during flight - Suggest Checking MPp's compasses Magnetic Field Strength levels prior to starting compass calibration.

Make sure you are in an area well away (+10-meters) from any sources of magnetic interference.  Make sure you do not have on you anything that could cause magnetic interference.

Make sure you rotate MPp drone around it's own axis as shown in manual.  Don't spin yourself holding drone to where drone is orbitting around you (your axis).

Check MPp's compasses Magnetic Field Strength levels after compass calibration, both bars should be short and green.  
4-20 21:29
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hallmark007
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I think it might be fair to say here, that some ridiculous theories get thrown about here on this forum.

Anyone with a modicum of savvy would realise , that the likelihood of getting magnetic interference when your 27ft in the air, unless your flying next to an airfreighter cruise ship it’s just inconceivable.

And furthermore we have seen this problem countless times, are we really expected to believe the air around us at heights of 10 metres or more is riddled with magnetic interference, it is such a far fetched idea that maybe there’s a movie in it.

We know and I know from much experience that Mavic Pro and Mavic Platinum have shown this exact trait when interference is contacted with on the ground, we all know with magnetic interference aircraft shows exactly same IMU HEADING warnings same yaw problems and the same result craft drops gps in favour of Atti mode.

It therefore beggars belief that we would even contemplate that our drone on so many occasions being flown in wide open skies would be in contact with magnetic interference , if this was the case I believe there would not be a drone in the sky.

Magnetic interference has to happen somewhere that’s a fact, it’s also a fact the the air we live in does not contain huge amounts of magnetic interference, so what is the most likely cause of the magnetic interference, “light bulb moment “ yes the ground, and it takes very little savvy to work this out, but it also takes very little to imply conspiracy theories, because your drone doesn’t show it on the ground doesn’t mean it’s not there.

It has been written here on the forum only this week, by a dji moderator,  that dji have made many improvements with compass in both M2 and MavAir so we see magnetic interference reported on the ground much quicker and much more precise, this is what’s called progress on hardware, we see very little of what we see on a weekly basis with Mavic Pro drones with new drones .
4-21 01:10
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hallmark007
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Goldchucker Posted at 4-20 19:21
Hi hallmark007

Quote:

Yes I believe all movements should be performed before taking off to the skies and this would undoubtedly show problems up so much quicker and craft would still be so much closer that we would almost certainly see much less crashes.


Raise AC to height of 8ft
Hover for 20 seconds
Fly forward 2ft
Backward 2ft
Left 2ft
Right 2ft
Up 2ft
Down 2ft
Yaw left
Yaw right
Each time returning to hover position
If you have a good horizontal each time, you will then know you have good GPS good IMU and good Compass, and your ready to fly.
4-21 01:18
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HedgeTrimmer
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Yes, there are ridiculous theories thrown about here on this forum.  One theory, a personal theory, (hint: not mine) is repeatedly thrown about because it sounds oh so good.  However it lacks evidence.  In fact that sound good theory often repeated goes against what thrower has also stated about drones and compasses.

We also know that when Mavic Pro encounters Magnetic Interference on ground, with properly calibrated set of compasses, that Mavic Pro will Flag magnetic interference via GO-4 App.

Anyone with half a brain would know, of a little something called false positives.  Also know enough not to jump to conclusions.  Unless of course jumping to conclusions helps to keep their personal only theory alive.


4-21 05:13
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v01d
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Hello,

I experienced this very similar behavior just this afternoon, totally freaked me out.
As far as I could see on the remote / my phone screen, immediately after take off it reported failed compass at least , and then I was looking in shock at my drone trying to understand what's it doing ..

It started well, booted, said ready to go. I didn't take long, took off. Once it took off, I don't think I even turned it or gave any other input, it just started to drift fly left at high speed, and, not responding to any of my inputs !! I was it total shock, because it was flying towards parking lot with people , it was was at a height to crash into someone's head....

I was panicking, didn't know what to do, my drone went nuts... Absolutely out of control, and I couldn't do anything with my remote controller..

In the end, _luckily_ , it crashed into a tree just before the parking lot. .. Could have been into a child's head, and I would be in big big trouble ..

What I wanted to ask you, how did you enable the log?  Is it automatically enabled for all drones? I would like to look at mine  or share it, to see if anyone could see what's wrong in the log.

From replies here it seems all to do with compass and calibration. I dunno, as drone said it's ready, and was giving green light GPS...

After the crash, I examined it, it looked oK, but gimball needed some physical adjustment.

This was in a new place, in the mountains. .. I struggled further that day to fly, because few occasions I was getting that Exit P-GPS Mode, and I coudn't not calibrate compass...
May be the mountains are cursed     Full of interference.

Anyway, really want to understand though the parking lot failed flight freak accident .. .I could have been sued or smth ...
4-21 05:20
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hallmark007
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I think this is clear proof , now maybe the idiots around here will show the proof of how in an open area you get magnetic interference, when flying at 10 metres high and higher , I don’t expect this proof will be shown because it doesn’t happen can’t happen and has never happened, our open air is not filled with magnetic interference that’s a fact and the sooner idiots stop implying this is the case without any proof the better for those who really want to learn.If you tell people that when the same problems happen with exactly the same consequences the same results the same log recordings, that there are infinite reasons for this, there is absolutely no logical or-savvy thinking for that, it’s completely daft and spreading it around here constantly with no proof only a ridiculous app which no one uses for very-good reason , telling people to bring metal detectors large magnets while trying to do something as simple as trying to fly a drone. It’s complete Nuts with no basis in fact absolutely none and spreading this complete rubbish which no one agrees with,helps no one .
Now he continues to ask for proof, but my turn now How do you get magnetic interference in open air away from any metal ar possible magnetic interference, I don’t suspect we will see it.
But below from a engineer who is hugely respected here on forums like inspire Matrice phantom etc.
A member who for a long time has been involved in beta testing dji products , who builds drones is very aware how these drones work and operate, I think I’m inclined to take heed of his advice, rather than taking the ridiculous overbearing fantasy theories from someone who doesn’t even fly his drone .



4-21 05:31
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hallmark007
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v01d Posted at 4-21 05:20
Hello,

I experienced this very similar behavior just this afternoon, totally freaked me out.

Just click on link and follow instructions.

http://www.phantomhelp.com/LogViewer/Upload/
4-21 05:43
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*DM*
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hallmark007 Posted at 4-21 01:10
I think it might be fair to say here, that some ridiculous theories get thrown about here on this forum.

Anyone with a modicum of savvy would realise , that the likelihood of getting magnetic interference when your 27ft in the air, unless your flying next to an airfreighter cruise ship it’s just inconceivable.

I have flown in very close proximity to a number of mobile phone masts and even then have not experienced any problems.

Photos are unprocessed
org_660dd8e5e690fbf2_1550923220000.jpg
org_06358dd63d59aa3b_1551019958000.jpg
4-21 06:02
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hallmark007
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*DM* Posted at 4-21 06:02
I have flown in very close proximity to a number of mobile phone masts and even then have not experienced any problems.

Photos are unprocessed

It is extremely difficult to come in contact with magnetic interference in the air, almost impossible in open air.
But we always have to be careful flying around masts or steel structures and once your aware of the dangers then that’s half the battle .
4-21 06:05
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hallmark007
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“We also know that when Mavic Pro encounters Magnetic Interference on ground, with properly calibrated set of compasses, that Mavic Pro will Flag magnetic interference via GO-4 App.“


How do we know this, is this just another thing that’s been made up, like bringing a large magnet metal detector around in your Mavic Pro. Kit, sometimes one just gets fed up with the most ridiculous idiocy being put forward and trying to make everything as complicated for other users, coming from someone who doesn’t even-fly his drone, well others can try decipher through his nonsense of offering up 10 things that may have gone wrong, but none that he can pinpoint, so users left with no answers except a handful of nonsense, this is not rocket science it’s flying drones, let’s try keep it there.
4-21 06:52
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v01d
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I think my error(s) were different to I put in this new thread, with the flight log:

https://forum.dji.com/forum.php?mod=viewthread&tid=187208
4-21 07:04
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hallmark007
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Again I offer more proof from one of if not the best source of outside information phantomhelp.

https://www.phantomhelp.com/tips ... 38#preflight-checks

4-21 07:08
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HedgeTrimmer
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To help you (the OP) out so you can separate what might have happened from sound-good theories.

The theory about compass clearing magnetic field resulting in new heading confusing IMU, was shot down by very person behind theory when person tried to make me look foolish with following: "Anyone with a modicum of savvy would realise , that the likelihood of getting magnetic interference when your 27ft in the air, unless your flying next to an airfreighter cruise ship it’s just inconceivable."

For person's clearing of magnetic field theory to be correct, the source of magnetic field would have to reach a distance of 235.3-feet and a height of 1781.1-feet according to flight logs.  The Yaw errors, (possible first indication of clearning of magnetic field), did not start until drone is 238.5-feet away from take off point.  Compass error which switches drone from P-GPS to ATTI mode (supposed indicating IMU is suddenly confused by now correct compass heading) does not occurr until drone is 273.8-feet away and 194.9-feet height.

Factor in the person's own remark of: "are we really  expected to believe the air around us at heights of 10 metres or more  is riddled with magnetic interference," and you have a Busted sound-good theory.

Knowing the person's recomendation of "Raise AC to height of 8ft  Hover for 20 seconds  Fly forward 2ft  Backward 2ft  Left 2ft  Right 2ft ..." came about because of now Busted theory, it brings person's recomendation into question.  Assuming for moment the person's Theory was correct, and magnetic field on ground could effect drone's compass at height of 194.9-feet.  What good is lifting drone to height of 8-feet, and flying drone forwards, backwards, left, and right?


Lastly please remember, I asked several questions and made a couple of suggestions for compass testing and calibration.  Never did I say there was magnetic interference at altitude of 27-feet or 10-meters as the person has tried to imply.  The person behind the Busted Theory knows that I have previously said that most common sources of magnetic field interference are limited to a distance of 1-meter when flying (not calibrating compass).  As such, person has shown to be more intersted in flouting his Busted Theory, than trying to figure out what really happened.

4-21 12:39
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Nordium
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hallmark007 Posted at 4-20 15:38
This is not completely unusual with Mavic Pro or platinum, although you had some flights that were ok this log looks familiar and I will explain below.

It looks like you took off close to or on concrete footpath and my guess is you picked up some magnetic interference, I will explain below what happens in this situation, regarding calibration it’s not necessary but it won’t do any harm if done correctly.

Thanks for your input - although I can't see how there would be any type of magnetic interference in the concrete on the sidewalk. I have 400+ flights on my MPP, which about 350 have been on this same exact sidewalk. No compass errors indicating that recalibration was needed ever, always got 18+ sats and a green "Ready To Go" before takeoff. This was the same for this flight - however it went completely berserk mid air, on the same flight route I've flown many times as well.
4-21 12:40
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Nordium
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HedgeTrimmer Posted at 4-20 21:13
Based on Flight Data as decoded, there is no indication of compass problem prior to and during take off in either CSV or extended CSV data files.

Compass Error occurs at 27.8-seconds and altitude of 194.9-feet.

Hi HedgeTrimmer, thanks for your response.
No compass warning or magnetic interference warnings prior to the time of takeoff. I've taken off from this same sidewalk 350+ times and never had to calibrate the compass on the spot before takeoff. The sensor interference levels have always been green with a status of "Excellent", with the two compasses having very short indication bars. I got a "Ready To Go (GPS)" message before takeoff just like every other flight.
The MPP's compass was calibrated successfully just a week beforehand, in a large open grass field away from metal and interference. I even moved my RC that had my phone attached to it across the field while calibrating. I followed the instructions shown on the GO4 app precisely, and never got a "Calibration failed" message. Please also note that after this calibration I had 8+ successful flights.

I know how the MPP's compasses function, and I've always taken super good care in my calibration techniques. I'm just really not sure why this would happen all of the sudden.
4-21 12:46
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Nordium
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HedgeTrimmer Posted at 4-20 21:29
I'm hoping an IMU and Compass recalibration will do the trick.

For purpose of seeing what might have caused Compass Error during flight - Suggest Checking MPp's compasses Magnetic Field Strength levels prior to starting compass calibration.

I've always followed this process when calibrating my compass. I've always calibrated it in an open grass field at a local park of mine, away from metal and any type of interference. Never got any error messages. The bars have always been short and green.
4-21 12:48
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*DM* Posted at 4-21 06:02
I have flown in very close proximity to a number of mobile phone masts and even then have not experienced any problems.

Photos are unprocessed

Previously posted a video of drone flying underneath a metal bridge down center of it's super-structure.  No crash, no errant behavior, fly nice and straight, despite steel beams all around it.

Also posted pictures of my own Mavic Pro preparing to take off from very close to semi-buried steel pipe and hovering with out problems slightly above steel pipe. Pictures here.
Thus, I believe your pictures are real.
4-21 12:53
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hallmark007
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Looks like the ridiculous theory of having a good calibrated compass at take off didn’t work as the fool told us, again something he has failed to prove like all the other rubbish he spouts.

It’s clear here all proof of what I have said I have proved, but some know all who doesn’t fly his own drone and continually tells others to carry magnets apps metal detectors so they can fly drones, is frankly the most ridiculous thing I’ve ever heard, he-knows nothing about drones and simply when asked to prove his completely ridiculous theory’s what do we get as proof.

Well 5his guy has the biggest mouth on this forum , he is continually trolling me asking almost of everything I sa to show proof, here for all to see I have completely backed up from top drone sources everything I said.
And what do we get from the Mouth, Nothing Nada Zilch in proof except to say he has tested 1 metre from the ground and a bunch of lies about me.

1/ I never implied or said you can get magnetic interference in the air, I clearly explained that interference was picked up on the ground, as soon as Craft leaves the ground interference is removed gone, the problem is with the IMU and it’s heading, you can clearly see in flight log at approx 160ft altitude a change in direction and-from here a chain reaction we see with Mavic Pro day in day out in an almost identical fashion, and No 10 different things don’t cause this as the mouth says.

But the biggest and most frustrating things about the mouth is, he can NEVER NEVER NEVER explain what happened or why, but for every time we see this exact same thing he offers 10 different theories NONE of which offers any idea of what happened and you would think by now having seen ten or twenty’s of this same occurrence he would have got the message.

I mean anyone who tells another user to take a magnet metal detector to a beach to test for magnetite is completely nuts, considering only last week he found from yours truly that many beaches contain magnetite.

He’s a con man but more than that is he has trolled me for almost 18 months with his ridiculous notions

I thing anyone who knows misinger who is one of the best and most knowledgeable people on drones and the mad angler , he has rubbished what both these guys clearly agree on , Oh But He Can Offer No Proof, I rest my case .
4-21 13:19
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hallmark007
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Nordium Posted at 4-21 12:40
Thanks for your input - although I can't see how there would be any type of magnetic interference in the concrete on the sidewalk. I have 400+ flights on my MPP, which about 350 have been on this same exact sidewalk. No compass errors indicating that recalibration was needed ever, always got 18+ sats and a green "Ready To Go" before takeoff. This was the same for this flight - however it went completely berserk mid air, on the same flight route I've flown many times as well.

That is the thing you won’t get warnings and gps won’t be effected, if you read the manual you will read never to take off or close to concrete structures, while your craft went out of control for a short time the fact that the systems recovered shows the rate of interference was small , I have seen much worse, but it is quite common in Mavic Pro and MPP, also with spark.

We very rarely see this with M2 or MavAir, M2 with only one compass and the reason is compass technology has greatly improved with these drones.
4-21 13:27
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Nordium Posted at 4-21 12:46
Hi HedgeTrimmer, thanks for your response.
No compass warning or magnetic interference warnings prior to the time of takeoff. I've taken off from this same sidewalk 350+ times and never had to calibrate the compass on the spot before takeoff. The sensor interference levels have always been green with a status of "Excellent", with the two compasses having very short indication bars. I got a "Ready To Go (GPS)" message before takeoff just like every other flight.
The MPP's compass was calibrated successfully just a week beforehand, in a large open grass field away from metal and interference. I even moved my RC that had my phone attached to it across the field while calibrating. I followed the instructions shown on the GO4 app precisely, and never got a "Calibration failed" message. Please also note that after this calibration I had 8+ successful flights.

Thanks for reply.  With that information, what you previously described, & flight log data - makes me think there was a temporary "Glitch" later on in flight.  Trouble is figuring out if "Glitch" was a compass error as a result of hardware problem or a false positive due to code problem.  With Yaw errors first showing up, there is possibility Inertia Motion sensor for Yaw was source of "Glitch", and MPp after couple cycles processed "Glitch" as a Compass problem.  

Similar to you, Fly mostly from a concrete area that has metal cattle panels in concrete as reinforcing mesh.  There is one area that does have steel rebar, which I avoid.  I know that area does cause magnetic interference for Mavic Pro Platinum.  From testing, the MPp can be rotated to various angles over rebar and go from Good to Go (Green) to Not Ready (Red).

Never been able to create a scenario where there was magnetic interference as shown by both compasses of MPp, and GO-4 fail to warn me.  Which is why I asked about what GO-4 was telling you before take off and at time of take off.

One possibility I can think of, and it needs testing, is as follows:

Drone is powered up sitting over buried steel, resulting in #1 compass being long bars of red, and #2 compass being medium bars of yellow - drone switches to #2 compass and indicates to GO-4 it is okay to fly.

Drone is powered up couple meters away from area, then placed in same exact location and same orientation.  Resulting in both #1 & #2 compasses having long bars of red - drone indicating to GO-4 it is not okay to fly.

4-21 13:38
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Nordium Posted at 4-21 12:48
I've always followed this process when calibrating my compass. I've always calibrated it in an open grass field at a local park of mine, away from metal and any type of interference. Never got any error messages. The bars have always been short and green.

Hi Nordium, you will see in this video exactly what happens when drone takes off from site where it has been in contact with magnetic interference. Whether by calibration or by placing the drone on the ground which the guy obviously does both, this drone was in contact with interference from take off, and warnings were not seen until well into flight .


You will notice no warnings showed up, you will clearly see the drone triangle showing bad heading you will also clearly see compass warning showed up well into the flight, you first see involuntary yaw movements followed by compass warning and of course bad heading, Also bare in mind this was a phantom 3 it’s perched almost 7 inches above the ground where as the Mavic is almost touching the ground, so chances of interference is greatly increased with Mavic you can see the involuntary yaw movements you can see compass warning and you can clearly see heading completely wrong, this is a great example of what can go wrong when you get interference on the ground .


4-21 16:31
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For those who try to demean below as a method of safety for craft when taking off for flying, it’s a procedure used by most pro flyers and by a huge amount of hobbyists and enthusiasts. Flying drone back forward left right etc, insures you don’t have compass problems and IMU problems, the attitude and correct gps lock are also shown. And the time taken preform this sequence and with the craft near by will insure a better chance if something is not right, again we have people around here who offer absolutely no help to others, but spend their time knocking very valid safety procedures and again from those who don’t even fly their drone .

This exercise as opposed to taking off straight up and forward which some here are now recommending , something that has and will continue to cause aircrafts to get into trouble that clearly could have been avoided in a lot of cases.


Raise AC to height of 8ft
Hover for 20 seconds
Fly forward 2ft
Backward 2ft
Left 2ft
Right 2ft
Up 2ft
Down 2ft
Yaw left
Yaw right
Each time returning to hover position
If you have a good horizontal each time, you will then know you have good GPS good IMU and good Compass, and your ready to fly.
4-21 17:19
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Since topic of "DJI GO does not always show a warning when the compass is being negatively affected by some type of external magnetic force" has been brought up.
Two things spring forth.
1) Should a drone crash in situation like one being discussed (minus good ending), the cause of crash would fall to DJI.  Being drone failed to detect and warn pilot that it's compass system was compromised.
2) Pilots need a way to detect external magnetic force prior to takeoff, not afterwards.  Which runs counter to previous remarks that magnetic field interference Apps are useless or ridiculous.  And runs counter to previous claims that drone itself is all one needs because it will detect sources of magnetic field interference.
4-21 18:33
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Have nothing against recommendation of "Raise AC to height of 8ft  Hover for 20 seconds  Fly forward 2ft  Backward 2ft  Left 2ft  Right 2ft ..." when it involves verifying drone is ready to fly and fly safely.

Unlike R.C. aircraft where a pilot can use RC to move flaps and ailerons up/down, and rudder left/right verifying correct response, a smart quadcopter (aka MPp) can't be tested for correct response without flying it.  Most practical method is to do a low hover and test drone's movements as suggested.

Despite another arm-waving hyperventilating false accusation, I (and no one else) has suggested here - taking off straight up.  What was called into question was validity of recommendation to avoid possible compass error occurring at a distance of 235.3-feet from takeoff point and a altitude of 1781.1-feet.  Which is the topic of thread as reported by OP and associated flight logs.
4-21 19:12
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Also bare in mind this was a phantom 3 it’s perched almost 7 inches above the ground where as the Mavic is almost touching the ground, so chances of interference is greatly increased with Mavic

Phantom 3's compass is located at base of landing arm.  
Essentially Phantom 3's compass is at ground level, not seven inches above the ground.

4-21 19:25
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Boffin
First Officer
Australia
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I was recently flying in an almost empty paddock close to where I live. As some cattle were grazing at my usual take off location I moved about 200m away and when hovering at about 10m to record the home point the magnetic interference message popped up so after landing my Mavic Pro I looked around on the ground for metal objects.

It was only when I looked up that I spotted the power line or phone line running to the distant farmhouse. It was about 30m directly above me with no warning flags. In the few years that I have flown at this site I never even knew that it was there (it's skinny and easy to miss)

After moving the cattle along I had a flight from my usual spot with no problems but have noted the location of that line!

So in this case the DJI warning worked perfectly to alert me and probably saved my Mavic Pro
4-21 22:02
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hallmark007
Captain
Flight distance : 4199094 ft
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Ireland
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I think the poster is now getting desperate.

He has already said here it’s not possible to get an interference warning well into a flight from interference picked up at take off, but the video clearly shows this happening and yet he has continued to troll bait me every time I mention the possibility of this happening, but his A*s was handed to him on a plate here.
He tries to do his usual squirming by pointing out where he thinks the compass of a p3 is, but what does this have to do with warnings of interference picked up at launch showing when craft it YES 1000 FEET AWAY, again he squirms to avoid answering what he clearly said was not possible and why , he was more interested in troll baiting than helping the OP

He has ridiculed two of the most respected people who operate on this forum and other forums helping others , Basically saying they don’t know what they are talking about. And why, I’ll tell you, because word for word they agree with everything I said and for no other reason.

He then comes up with his usual five different things that happened, I mean who does that, if I for a moment though there were five possibilities for what happened my clear advice would be contact dji and get their opinion.

But what is this case about, well we know that the symptoms we see here are symptoms we have seen hundreds of times before with Mavic Pro and similar amount of cases with spark and phantoms, common take off areas around or on concrete close to car or close to metal structures, we see craft taking off and in some cases which I expect is because of levels of interference craft takes off craft is in the air close by immediately gets warnings compass error IMU heading exception craft going to Atti mode and control is lost usually crash, looking at log we always see first a yaw error, other cases like we see with OP’s log craft I suspect interference not so strong but same warning first yaw issue compass error IMU heading Atti mode.

So what is it telling us , well it’s all pretty simple same symptoms same diagnosis, we see doctors apply same rules, we see detectives apply same rules with serial killers, in fact in everyday life we operate these same principles .

But what is our other poster expecting to accept as helpful, well it goes something like this, Same Symptoms, But it can’t be the same problem because he will now give five different theory’s  for this problem and in other similar cases he gives five totally different theory’s and low and behold he offers as he did here not a modicum of proof, I laughed when I read in light of what the OP said that he had 350 flights completely troubled free, and he is met with the answer , this could be a code problem.

I think what we have here is one clear case of troll baiting and nothing else, and it is done with not a single thought for the OP or his problem, to try to get his ridiculous theory’s across he takes no prisoners and rubbishes well known highly knowledgeable people here on this forum.
He trolls me on almost every thread I post to, he constantly views my homepage for whatever sick reasons I don’t know, but sometimes ends up trolling me on phantom forum without realizing it, he needs to stop , not for my sake but for the sake of people who genuinely post looking for help.
It is surely no help giving five different theory’s to someone, surely if there were five or more different reasons for someone’s problem and you didn’t have a modicum of proof you would do the right thing and advise contacting dji for there help.
4-22 01:52
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HedgeTrimmer
Captain
United States
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hallmark007 Posted at 4-22 01:52
I think the poster is now getting desperate.

He has already said here it’s not possible to get an interference warning well into a flight from interference picked up at take off, but the video clearly shows this happening and yet he has continued to troll bait me every time I mention the possibility of this happening, but his A*s was handed to him on a plate here.

Reported for usual behavior of Trolling to start trouble.
4-22 07:47
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hallmark007
Captain
Flight distance : 4199094 ft
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Ireland
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He’s a bit late to the party every time has trolled me it’s been reported, I have seen watchberger bullied off this forum by this guy it won’t happen to me . At least we know he had no proof so here this ends .
4-22 07:56
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