Compass Calibration Required

[flyNfrank]

I'm curious. How can it be determined from the log if the compass had been calibrated before flight? I'm presuming that you're looking at the .csv that gets generated by djilogs.com from the FlightRecordXXX.txt file.

That's correct.

 

[gunslinger]

Gentlemen... please keep this civil before warnings begin to fly...

Thanks...
-slinger

 

[BudWalker]

I subscribe to the notion that calibrating too often increases the chances that a bad calibration will occur. To test this I attempted to calibrate in situations that would produce a bad calibration. First, I tried calibrating next to my truck on it's North, East, South and West sides. But, if I was too close I would get a error message saying I was "too close to electromagnetic interference". The closest I could get without the error yielded a calibration with a MOD value of 1650. The X, Y and Z values in 8 cardinal directions weren't that bad either. Although I'm not gonna fly it with this calibration (I'm not that brave) I can't conclude that my attempts at a bad calibration would lead to a undesirable flight. Maybe I need to be more creative on things that will produce a bad calibration - like maybe a steel pipe directly underground?

 

[BudWalker]

That's correct.

View attachment 29618

Well, duh. I misinterpreted what you said. I thought you meant that the compass had been calibrated, possibly on a previous flight. I presume this log means that calibration took place on this "flight" prior to launch. This was the claim being made by the pilots supplying the .txt files?

 

[ianwood]

Needless calibration is dangerous. Plain and simple.

 

[BudWalker]

It seems there are a lot of assumptions about what exactly is occurring during calibration which lead to some pretty creative 'theories' about this and that.

You can visit this site or find your own but it explains the calibration process pretty well.

Magnetometer - VectorNav Library

Interesting. It would seem that compass calibration process in the Phantom is determining those 12 parameters that yield the nice round, centered, normalized circle representing the magnetometer outputs. But, in addition, compass calibration in the Phantom determines those 12 parameters such that the circle has a radius that corresponds to a MOD value close to 1500. Although the circle radius isn't addressed in the article a scalar multiplier of the M matrix could be used to adjust the radius.

 

[sergekouper]

I am very procedural when I go flying, my check list is longer than my left arm. But I feel inappropriate to calibrate the compass at every flight (why not every battery?) DJI has been clear: They recommend calibrating at every new location (figures are 150 miles I believe.) not at every flight. If it was necessary, they would have mentioned it. So in the name of what someone decides and recommends (Based on what information?) that the calibration must be done at every flight? Put it simple, to each his own, but DJI DOES NOT recommend to calibrate at each flight. Any contrary recommendation is misleading and must be corrected. I wonder what's the point to spread wrong information on the forum, when all what we need is clear infos to avoid mistakes.
PS: I don't wait to be at 100 miles to recalibrate, but when I fly in a 10 miles radius I'm not bothered, and not taking any risk)

 

[N017RW]

Distance is a catch-all.

Magnetic field conditions MAY change at any distance from the calibration location.

I once travelled 600 miles without the need to recalibrate.

 

[brianb87]

It is not advised to calibrate your compass before every flight.
In fact unless you move 100miles from last compass calibration point, it should be just fine. ;-)

Why would You do it before every flight? Curious
What are you trying to accomplish...?

RedHotPoker

I fly the same place every time (as of now) and it ask me to calibrate always. Your saying don't?

 

[brianb87]

When you power on your R/C (remote/controller) with your device plugged into the mini usb, the 1st time it should ask which app you would like to associate the R/C with. At this point you should also be able to select whether you want it to access the app just this time only, or always. It's best that you select this to always use the app you are currently using it with for the upcoming flight. Unfortunately the main reason for this is should your device overheat and cause a complete shut down, as long as you have the setting to always connect to the app with the device being used, it will automatically start back back up in the event of a shut down.

The main purpose for this thread is to inform you to calibrate the compass prior to each flight. Other then laziness, there is no excuse to not calibrate before each flight. DJI has built a audible message to complete the aircraft status prior to flying. When you click to enter camera view, you are directed to the Aircraft Status section. And right there is plain sight is the option to begin the Compass Calibration process. When completed you must have flashing green lights, if not then it is a failed calibration and you will need to run the process once again. The system will not pass a failed process.

I would read the instructions.. Not sure information on this site holds any weight. Not saying anyone is right or wrong.

 

[Meta4]

I fly the same place every time (as of now) and it ask me to calibrate always. Your saying don't?

If your Phantom is asking you to calibrate the compass, that is because it is detecting a magnetic field different from what it expects. .
You need to look at where you are calibrating and identify the source of that field.
For example, are you on a manhole cover, car roof, concrete with invisible steel reinforcing, a table with a steel frame or something like that?

 

[III% Streve]

I fly the same place every time (as of now) and it ask me to calibrate always. Your saying don't?

Thats covered by the part that says not to calibrate or take off near metal

Sent from my SM-G920P using Tapatalk

 

[Meta4]

Compass calibration is one of the most misunderstood aspects to Phantom flying.
As a result of the misunderstanding, all kinds of theories and almost superstitious rituals have developed.

The idea of calibration is to make certain the GPS locator is pointing to the correct longitude, latitude, and altitude.

This is an example of the kind of complete misunderstanding that surrounds compass calibration. I've seen this one surface a number of times.
Compass calibration has nothing at all to do with GPS location. NOTHING
The Phantom's GPS and compass are two unrelated systems.

Not only should we be recalibrating at every new site and on every new day .....

It's always interesting to hear this. It doesn't come from DJI.
They have never recommended calibrating every flight or every day.
And if it was important, they would have.
It's people that don't understand compass calibration that suggest this.
They don't understand what it is or when it is necessary but feel that it is about safety, so more safety can't be a bad thing.
But it can be when you don't understand what you are doing and why.

When I hear hacks talking about how unnecessary it is to do a recalibration I roll my eyes thinking they will be posting the next "I didn't see that coming" thread.

And when I hear someone advocating calibrate every flight, I cringe because it is someone with a very poor understanding that can lead to unsafe flight rather than what they intend.

For anyone uncertain about calibration I strongly suggest reading Ian Wood's excellent explanation. Compass Calibration, A Complete Primer | DJI Phantom Forum

 

[N017RW]

I would read the instructions.. Not sure information on this site holds any weight. Not saying anyone is right or wrong.

The advice [here] holds plenty of weight.

YMMV

 

[brianb87]

Thats covered by the part that says not to calibrate or take off near metal

Sent from my SM-G920P using Tapatalk

Hey Streve!

Think it could be my plastic case I am talking off from? I'm sure it has some metal in it.

 

[brianb87]

The advice [here] holds plenty of weight.

YMMV

There are only a few people I trust on this forum. I am kinda new and already know who to take advise from and not.

 

[N017RW]

Trust [all] but Verify!

(Pres. Reagan quoting some Russian proverb AFAIK)

 

[brianb87]

Trust [all] but Verify!

(Pres. Regan quoting some Russian proverb AFAIK)

Thank you.. You worded it better then me. People here get offended easy.

 

[RedHotPoker]

I only meant to share what I learned from the guys with years of experience. The Phantom 3 is a very smart machine, but much like a computer, is only as smart as the user, and that's you.
I don't mind if others want to do the drone dance/compass calibration, every flight, every fresh battery, or every time they pee. Hahaha

I found in my territory, this far N.in Alberta It wasn't necessary.
YMMV, and I hope it does. ;-)

Happy hovers, and safe land, , , bounce, landing...

RedHotPoker

 

[III% Streve]

Hey Streve!

Think it could be my plastic case I am talking off from? I'm sure it has some metal in it.

The hinge is all plastic? The latches? The hinge in the handles? The wheels? It couldn't be more obvious that there is a magnetic field from SOMETHING that is giving you a need to calibrate constantly, and consistently. It don't care you look at it, or value anyone's advice.. it couldn't be more obvious that something is not totally legit with what you are doing or using.