compass error

[m0j0]

It happens due to magnetic interference and can be terrifying when it happens while airborne. If a person is lucky, they can finesse the drone down. If not, it's going in big circles until it hits a tree.

Calibrating your compass absolutely will not prevent magnetic interference. Magnetic interference is introduced from flying to close to metal. I have a solid calibration on my compass and have not calibrated it sense I received the aircraft. I have flown in 20 different states and just returned from the Bahamas. Where I flew in three different ports.. Not a single hiccup. I rarely disagree with you but on this topic I do. Sense my Phantom 3 Pro I have taken the stance of "get a clean calibration and leave it alone" unless prompted or the preflight checks are irregular.

The best way to avoid it is to calibrate your compass before every flight. If it continues to happen in the same place you have flown before many times without a compass error, it's possible that one of your compasses is malfunctioning.

You would know this better than i would but still... If you have a good calibration in an area why would you suggest a new calibration in the same area. If it is off I would be concerned with my launch point - making certain the bird wasn't over something metal. I would land it and launch it from a different area. Which again if you have a clean calibration in an area I have found no reason to calibrate. Hundreds of flights on my Phantoms and Mavics without calibrating. I think the problem with the magnetic interference and or accompanying compass error lies outside of calibrating - a bad calibration is more likely to cause a problem than leaving a good calibration alone. Just my .02

 

[m0j0]

There are magnetometer apps, but there is a much simpler method - just ensure that the aircraft orientation arrow on the map screen is pointing in the same direction, relative to north, as the aircraft is actually facing. If it is then the IMU yaw value will be correctly initialized.

Exactly.. part of the my checklist is to check the arrow. Check the orientation on the map. Fly straight out and straight back. I could tell if there was a problem by watching the flight. If there was an ARC in the flight path there is a problem. I recall one time where my Phantom flew in an ARC that was about 5 feet in the 50 feet I flew out. Pulled the stick back it flew the same arc. I did not recalibrate. I moved to a new location and flew with not problems. Obviously there was a magnetic issue. If I had recalibrated in that area I would have introduced an issue.

 

[Former Member]

Calibrating your compass absolutely will not prevent magnetic interference. Magnetic interference is introduced from flying to close to metal.

If your compass is showing out of calibration, and you have tried to take off from different launch points, it's time to calibrate the compass.

I have flown in 20 different states and just returned from the Bahamas. Where I flew in three different ports.. Not a single hiccup. I rarely disagree with you but on this topic I do. Sense my Phantom 3 Pro I have taken the stance of "get a clean calibration and leave it alone" unless prompted or the preflight checks are irregular.

Thats fine. But again, if you are trying to take off from multiple launch points and it wont let you, there is every reason to calibrate the compass.

If you have a good calibration in an area why would you suggest a new calibration in the same area.

Different situation than above. If you fly from the same location every day, and then one day it's requesting calibration, why not calibrate it? If it doesnt calibrate, then I suspect a compass issue.

 

[Hayabusa]

Without that modification there is no mechanism on a Mavic to select ATTI mode. That's why I strongly recommend the modification, replacing either sport or tripod (on the M2). I replaced sport mode on my MP and M2P since you can also set the maximum pitch in ATTI mode to sport-mode values - just in case anyone feels they need it for performance in high winds.

How do you modify to get ATTI mode?

 

[sar104]

How do you modify to get ATTI mode?

This describes the Mavic 2 modification, but the Mavic Pro is basically the same.

Mavic 2 Atti mode

 

[m0j0]

If your compass is showing out of calibration, and you have tried to take off from different launch points, it's time to calibrate the compass..

True but that is not what happened here. He launched and then during the flight received a compass error. That is more likely a function of flying into some "magnetic interference." I often get that error when I fly near the saw mill with my Phantom.

Thats fine. But again, if you are trying to take off from multiple launch points and it wont let you, there is every reason to calibrate the compass.

We agree on this but this is not the scenario we have for this. I would disagree with a mentality of calibrating every time you fly or calibrating because you get a compass error. If you have that problem in flight then you need to evaluate your flight path and determine what might have been the issue. It is more likely an external problem than it is a mechanical issue in the Mavic.

Different situation than above. If you fly from the same location every day, and then one day it's requesting calibration, why not calibrate it? If it doesnt calibrate, then I suspect a compass issue.

If it requests a calibration I would move locations first. to make certain that something magnetic was not causing the error. Sometime moving 20 feet can resolve the issue. If you are certain that the location is not the issue and you are in a clean magnetic environment and you are still receiving the calibrate msg. Then I would calibrate.

More importantly I will not calibrate because I receive an error. The reason I won't is because I know I have a solid calibration in a magnetically clean environment. If you calibrate because you are prompted to...without ensuring that the location is not magnetically corrupt you will introduce a bad calibration. That will cause you far more problems. I won't go in to detail but the calibration thread spells out some very sound practices for calibrating. I can 100% say I have witnessed bad calibrations cause crashes from a pilot that was a "calibrate every time he flies guy." Calibrated his Phantom in a bad spot took off. Things went wonky couldn't control it crashed it into the a chain link fence at the tennis courts. It fell about 20 feet onto the asphalt. Done! He got a P4 and a lesson out of it.

 

[sar104]

True but that is not what happened here. He launched and then during the flight received a compass error. That is more likely a function of flying into some "magnetic interference." I often get that error when I fly near the saw mill with my Phantom.

Actually it's far more likely that he powered up the aircraft where there was local magnetic interference and then flew out of it. That's a much more common and pernicious problem.

 

[m0j0]

Yes but that usually results in an immediate issue. As soon as you fly away from the magnetic interference the bird gets wonky. I have seen that happen a number of times. My personal compass errors have all occurred during flight and were because of "local" interference. The one below is a sawmill that is 100% metal. This happened with my Phantom 3, I was pretty close. I haven't flown that close with the Mavic so I don't know if the same problem would occur.

Several other times I received a compass error, again P3, was in a remote area. Every time I flew over a certain area I would get a compass error really a weird phenomena. I would be flying out in the desert and when I get near this spot compass error I would keep flying and it would go away. It's a repeatable error. I have no idea why as there was nothing on the ground or nearby that would be an obvious cause of the compass error. Maybe it was electromagnetic ?? No idea.

 

[Former Member]

OK I guess the big question is, is the compass error calibration notice we receive in DJI go actually misleading the majority of the time?

It sounds like it could be masking something, or the coppice could actually be in calibration but not allowing you to take off until you satisfy its requirements which could be unnecessary.

 

[sar104]

Yes but that usually results in an immediate issue. As soon as you fly away from the magnetic interference the bird gets wonky. I have seen that happen a number of times. My personal compass errors have all occurred during flight and were because of "local" interference. The one below is a sawmill that is 100% metal. This happened with my Phantom 3, I was pretty close. I haven't flown that close with the Mavic so I don't know if the same problem would occur.

Several other times I received a compass error, again P3, was in a remote area. Every time I flew over a certain area I would get a compass error really a weird phenomena. I would be flying out in the desert and when I get near this spot compass error I would keep flying and it would go away. It's a repeatable error. I have no idea why as there was nothing on the ground or nearby that would be an obvious cause of the compass error. Maybe it was electromagnetic ?? No idea.



View attachment 61719

OK yes - that will do it too. There are areas where ferrous deposits in the ground exhibit a significant magnetic field.

 

[m0j0]

OK yes - that will do it too. There are areas where ferrous deposits in the ground exhibit a significant magnetic field.

That seems likely where I was flying..

 

[Meta4]

That seems likely where I was flying..

It would have to be a massive (and probably highly commercial) iron ore deposit and you'd still have to be flying quite low for it to register on the compass.
Flying this close to 100000 tons of steel has no affect on the compass at all.

 

[m0j0]

It would have to be a massive (and probably highly commercial) iron ore deposit and you'd still have to be flying quite low for it to register on the compass.
Flying this close to 100000 tons of steel has no affect on the compass at all.

Don't know - When I get back there I will walk it and see if I can get it to happen again. I know exactly where it happens. Usually I am about 30-50 feet above the ground when it happens. Green to Yellow on the screen and Compass Error... I keep flying a second or so back to green. I might have the flight data somewhere I will post it if I find it. There is nothing on the ground aside from mesquite bushes.