Does everyone recalibrate.............

[TS_Thomas02]

As I understand it, the purpose of the calibration is to help give the drone the best possible valuation of what the local "magnetic variation" value is and more importantly, where it senses that magnetic north is. Variation is the angular difference between true north and magnetic north. The drone should be able to compute a pretty solid true north value (if it even needs it) by sensing the magnetic north, applying the "MagVar" value to it from a position database. Position comes from the GPS. Your phone would definitely do all this too using the same process if you're selecting the True North option. Since one can go across one state in the US and only pick up a degree of variation, I don't think it has to be a very big database by today's standards. Ultimately, I'm not even sure I'd see a reason for the drone to need True North, but if it's going to run with Mag North, it needs to be a stable number. It's magnetic sensor makes a reading from Maximum to Minimum and it has to compute how that relates to where North would be. (This, I believe, is at the heart of why calibration has to happen sometime.) Therefore, no taking off from the top of a car. Maybe not even from a steel-hulled boat/ship or a steel bridge that's underfoot. My gut tells me the drone doesn't need to worry about True North, but be vary wary of what could be causing a magnetic fluxuation in the compass from where you take off.

 

[Meta4]

As I understand it, the purpose of the calibration is to help give the drone the best possible valuation of what the local "magnetic variation" value is and more importantly, where it senses that magnetic north is.

This is a common myth.
Compass calibration has nothing to do with magnetic variation or where you are.
To get a proper understanding of compass calibration read the first post in this thread:

A short explanation of compass function, calibration and errors.

BACKGROUND The aircraft compass is often misunderstood, both in terms of function and purpose, but it is important to understand what the compass measures, why, and what happens to that information. At the most basic level the purpose of the compass is to measure the earth’s magnetic field in...

mavicpilots.com

 

[SkyeHigh]

As people are repeatedly being advised, read the first post in the thread. It was created by SAR104, a physicist at Los Alamos Laboratories and is source of far more knowledgeable and accurate information than you will read in DJI’s manuals.

Writing technical manuals is a far more complex task than most would believe and doing so while translating between languages even more so.

There are many errors and contradicting statements in DJI’s manuals.

 

[Alex 007]

My Mavic Mini nearly always come up with Compass calibration required every time I fire it up in a different location to the one I last flew at.

I therefore just do it. Pretty quick and easy especially with the Litchi App that has voice prompts.

 

[Twalker]

I've just read some information regarding recalibration of the IMU and Compass
and it strongly advised doing this each time after a car journey. So for me and probably
many others who don't always fly without a car trip to where your flying from, this basically
means each flight. Is this right or necessary in your opinions.

I agree with "recalibrate on request" only. One thing (I read this somewhere else first) I always do is, immediately after take off is I hover and do a slow 360 turn on the spot which I think settles the compass down. I've flown a M.Pro for over 4 years and never had a problem.

 

[Meta4]

One thing (I read this somewhere else first) I always do is, immediately after take off is I hover and do a slow 360 turn on the spot which I think settles the compass down.

A digital compass sensor doesn't need any "settling down".
It will work just fine without that ritual.

 

[BenAir]

I think its to do with how the difference between true and magnetic north changes when you travel a significant distance
The previous and current GPS fix is likely an input and trigger for a calibrate

 

[Meta4]

I think its to do with how the difference between true and magnetic north changes when you travel a significant distance
The previous and current GPS fix is likely an input and trigger for a calibrate

Despite the number of people that keep repeating this myth, it isn't.
It has nothing at all to do with magnetic variation or where you are.
Read the first post of the link I posted back in post #42 to find out what compass calibration really does.

 

[Repaid1]

Despite the number of people that keep repeating this myth, it isn't.
It has nothing at all to do with magnetic variation or where you are.
Read the first post of the link I posted back in post #42 to find out what compass calibration really does.

You can have people read, but you can't make them learn. This thread needs closed IMHO This trival discussion has surpassed any usefulness....and I for one am tired of it coming up daily with new posts.

I have a P3P (Early DJI) it has had 1 (one) compass cal out of the box (That is +5 years, folks). It has been flown from west coast USA areas to east coast USA and some points in between (not literally). I have never had any error other than having to move it a few feet from launch to clear any error. So if it can RTH (Some 1000 times) and never miss a beat, than I am pretty sure any newer (Better?) DJI will do the same.

I have owned 4 DJI aircraft up to my latest M2Z. It has asked maybe a handful of times to recal compass, I have only done so once and that was just because I wanted it off my screen when I wanted to adjust settings in a known bad area, I then before next flight took it outside and clear, and did a recal to clear bad compass cal.

You gang have been advised of the usefulness of the cal, why you shouldn't be doing subsequent cals. Let's be done with the discussion. Cal or Cal not...PFffttt.

 

[dronerdave]

This is a common myth.
Compass calibration has nothing to do with magnetic variation or where you are.
To get a proper understanding of compass calibration read the first post in this thread:

A short explanation of compass function, calibration and errors.

BACKGROUND The aircraft compass is often misunderstood, both in terms of function and purpose, but it is important to understand what the compass measures, why, and what happens to that information. At the most basic level the purpose of the compass is to measure the earth’s magnetic field in...

mavicpilots.com

THIS!

 

[halifax]

there is no need to recalibrate ,most times when a compass calibration comes up, is because of some metal near to the take off point ,and just moving a couple of feet will make the message go away
in over two years of ownership of my MPP i have calibrated the IMU once when i first aquired it and the compass probably no more than three times in total after over 600 flights in many places around Wales

I've noticed that I get a calibration request often if I put one of my strobes on the underbelly of the aircraft before startup. Thus, I wait until after going through the start sequence. Never had a problem, but ...

 

[Meta4]

I've noticed that I get a calibration request often if I put one of my strobes on the underbelly of the aircraft before startup. Thus, I wait until after going through the start sequence. Never had a problem, but ...

You would be getting the calibration request because you've added to or changed the magnetic fields that are part of the drone.
That's completely normal.

 

[Deleted member 133794]

Thanks to everybody who has answered my original question, this seemed
to be the best place to ask, seeing as it was mavic related. I've now learned
the general rules of CALIBRATION of the drone. ??

 

[Zonian]

I've just read some information regarding recalibration of the IMU and Compass
and it strongly advised doing this each time after a car journey. So for me and probably
many others who don't always fly without a car trip to where your flying from, this basically
means each flight. Is this right or necessary in your opinions.

In over 3 years I have only calibrated compass and IMU once...when the Mavic Pro was new.

 

[sharkface]

redo the IMU if you are in a diffrent curvature of the planet. redo the compass every time . ... buuttt ! I don't.

 

[Meta4]

redo the IMU if you are in a diffrent curvature of the planet. redo the compass every time . ... buuttt ! I don't.

There's normally no need to recalibrate the IMU unless the drone has had a bad crash.
Where you are on earth has no effect on the IMU.

Recalibrating the compass before a flight is completely unnecessary, unless you've added or removed accessories from the drone.

 

[sharkface]

There's normally no need to recalibrate the IMU unless the drone has had a bad crash.
Where you are on earth has no effect on the IMU.

Recalibrating the compass before a flight is completely unnecessary, unless you've added or removed accessories from the drone.

it's just what most Youtube and comments say as a general census. you can fly anyway you want as long as it is legally. ?

 

[Meta4]

it's just what most Youtube and comments say as a general census. you can fly anyway you want as long as it is legally. ?

Youtube is the last place to find factual information.
Understanding how your drone actually works is a better idea than taking advice from Youtube people that have no idea what they are talking about.
Go back and read the first post in the thread that I linked to in post #42 to get an understanding of what compass calibration actually does and when it might be required.

 

[umanbean]

it's just what most Youtube and comments say as a general census.

Youtube?..... Please don't tell me you rely on that huckster-ridden excuse for a plausible website to get your facts. I've been reading this and the PhantomPilots forum for many years, and I'd fully believe Meta4 and sar104 over ANY video on youtube.

If you haven't yet, please read the first post in the link Meta4 provided above.

 

[sharkface]

Youtube?..... Please don't tell me you rely on that huckster-ridden excuse for a plausible website to get your facts. I've been reading this and the PhantomPilots forum for many years, and I'd fully believe Meta4 and sar104 over ANY video on youtube.

If you haven't yet, please read the first post in the link Meta4 provided above.

if there is wisdom in the masses and you do not listen? you could very well be the massiveass . I learned a lot from people who know more than you and I do.