I'm wise enough to honestly admit embarrassment. Compass calibration ... This issue was discussed in the past to a boredom since Phantom and Inspire drones arrived. It was concluded by many expert contributors to all related forums that compass calibration for DJI drones should be performed as seldomly as possible. Perhaps after firmware upgrade, together with necessary IMU calibration, or after traveling several hundred miles to a new location. It was also said that occasional and dreaded "compass error" warnings does not necessary require immediate "on the spot" calibration dance. In contrary, compass calibration performed in magnetically polluted environment may render a catastrophic misbehaviour.

I just recently acquired Mavic 2 Pro drone as an addition to my photographing/filming fleet of bigger cousins. In my arrogance I didn't even bother to read the manual ... I did routine firmware updates, IMU and compass calibration, all sweet and dandy. Soon after traveled a mere 80km to do some filming and ... boom, Mavic need compass calibration! Back home again, dreaded compass thing ... WTF?

That's where my embarrassment comes from. Read the manual, you idiot! Page 65:

"It is recommended that the compass is calibrated in any of the following situations:
1. Flying at a location farther than 31 miles (50 km) away from the location the drone was last flown.
2. The aircraft has not been flown for more than 30 days."

I didn't see this coming! This is different from what we used to know until Mavics arrived. Why? Is it advanced, more efficient compass technology? Just curious ...

Yes, I've had to calibrate the compass on the MP2 outside of 35 miles from the last location.

... I'm not sure what happen here with my reply, had to erase duplicated content ...

What is the big problem?  It takes less than a minute in the field and I have done it dozens of times without issue.

I believe , the first mavics had 2 compasses and 1 imu
The mp2 has 1 compass and 2 imu’s
Maybe that has got to do with callibrating the compass, just to be on safe sight

parkgt214 Posted at 12-14 13:55
What is the big problem?  It takes less than a minute in the field and I have done it dozens of times without issue.

There's no problem nor issue. It's just my plain curiosity, eagerness to know why. It's been told many times before to avoid frequent compass calibration as much as possible ... until now. With introduction of Mavic class drones the requirements are quite different ...

Since Mavic Air , sensors seem to be set to force calibration when you travel certain distance, there is no way around this, I don’t believe it has anything to do with the compass needing calibration , only thing I can say about it is, you will find it very hard to pick up any threads where people are discussing compass problems in M2 or M2Z, this is a positive I suppose , but I suspect it's more to do with it being much better sealed .

Hi, Should the compass on a Mavic Pro be calibrated even after the message "home point has been recorded' message is received, before flying after long period / 50km from the previous flight etc.?

Peera Posted at 1-10 23:20
Hi, Should the compass on a Mavic Pro be calibrated even after the message "home point has been recorded' message is received, before flying after long period / 50km from the previous flight etc.?

No ... just fly and enjoy the drone.
You don't need to recalibrate the compass just because you've travelled or not calibrated for a while.

Labroides Posted at 1-11 01:47
No ... just fly and enjoy the drone.
You don't need to recalibrate the compass just because you've travelled or not calibrated for a while.

That is and was always true with Phantom/Inspire class drones ... Not anymore with Mavic generation. The manual clearly recommend periodical compass calibration after prolonged parking and/or travel distance bigger than 50Km. Hence my OP.

Said that, I wouldn't recommend performing calibration on the spot only because the app is dispaying warnings and demand immediate intervention. I will move somewhere else to confirm that compass reading bar is way off accepted values indeed.

Matthew Dobrski Posted at 1-11 12:03
That is and was always true with Phantom/Inspire class drones ... Not anymore with Mavic generation. The manual clearly recommend periodical compass calibration after prolonged parking and/or travel distance bigger than 50Km. Hence my OP.

Said that, I wouldn't recommend performing calibration on the spot only because the app is dispaying warnings and demand immediate intervention. I will move somewhere else to confirm that compass reading bar is way off accepted values indeed.

Not anymore with Mavic generation. The manual clearly recommend periodical compass calibration after prolonged parking and/or travel distance bigger than 50Km.

The manuals have been incorrect on the subject of compass calibration for years, causing no end of confusion and even superstition on the subject.
The got it right finally with the P4 pro but then went back to misleading owners again after that.
ANd just to cap off their compass calibration  nonsense, for some M2 pros they make you recalibrate after so many days or kilometres ... even though there is no physical reason why it would be needed.

But the question I reponded to was about the Mavic Pro which won't force you like that.
It should only ever need compass calibration if the drone is modified.

Labroides Posted at 1-11 14:29
Not anymore with Mavic generation. The manual clearly recommend periodical compass calibration after prolonged parking and/or travel distance bigger than 50Km.

The manuals have been incorrect on the subject of compass calibration for years, causing no end of confusion and even superstition on the subject.

Now you understand the title of my post ... Still, I believe they changed something in Mavic 2 Pro firmware to make compass more sensitive to location changes. Oh, well ...

Matthew Dobrski Posted at 1-11 14:43
Now you understand the title of my post ... Still, I believe they changed something in Mavic 2 Pro firmware to make compass more sensitive to location changes. Oh, well ...

I still do not believe the requirement to calibrate the compass frequently, particularly the bit about doing it after the aircraft has been lying idle for more than 30 days. There is simply no scientific reason or background for the time requirement. It is technical gobbledegook, but DJI give it legs by putting it in the manual.

Compass calibration has absolutely nothing to do with calibrating it to point in the correct direction, because at no stage during the calibration process do you ever point the compass in a known accurate direction. Nor does it compensate for magnetic variation if you move 50 km from the last location, for exactly the same reason, otherwise you would have to point it in a known direction at some point in the calibration process.

The reason for compass calibration is to identify local influence from ferro-magnetic materials. When the aircraft is constructed, it is almost impossible to use materials in the construction that are not magnetic, so the final product is surrounded by small components that have an adverse effect on the built-in compass chip. Performing the calibration lets the control processor identify the degree of interference from the local magnetic objects, it then stores that information and mathemetically adds or subtracts it from the compass reading to arrive at an accurate heading. So, unless you add any part to the aircraft, remove any part, or change anything in the construction, the calibration is not necessary.

The only possible reason for the time requirement is if the calibration information is kept in non-volatile memory in the aircraft, and that memory is prone to being corrupted over a period of 30 days or more. But if that is the case, then DJI are using pretty dodgy components in their construction.

Geebax Posted at 1-11 15:15
I still do not believe the requirement to calibrate the compass frequently, particularly the bit about doing it after the aircraft has been lying idle for more than 30 days. There is simply no scientific reason or background for the time requirement. It is technical gobbledegook, but DJI give it legs by putting it in the manual.

Compass calibration has absolutely nothing to do with calibrating it to point in the correct direction, because at no stage during the calibration process do you ever point the compass in a known accurate direction. Nor does it compensate for magnetic variation if you move 50 km from the last location, for exactly the same reason, otherwise you would have to point it in a known direction at some point in the calibration process.

Huh, technology has changed since Phantom era ... Do you believe that Skydio's battery is held by magnets only?

Matthew Dobrski Posted at 1-11 15:31
Huh, technology has changed since Phantom era ... Do you believe that Skydio's battery is held by magnets only?

I don't know anything about the Skydio, but it would seem unlikely. The aircraft would have to have a compass, and it would therefore have to be a solid-state one, and any magnets would affect it. Why would you build in a magnetic interference source?