Well, today I went out to take some videos shots for local businesses that will be a part of our community promotional video for Point Place.  
As soon as I took off, I noticed that the UAV was leaning to one side, much like most of my shipmates when the return from a night off the dock.  
Well, despite its inebriated appearance, I still got the shots I needed and then brought the P4P home to sweep the grass I cut from my driveway and sidewalk.  
     -What?  None of you do that???  

ANYWAYS, when I got home, I recalibrated the IMU and the drone sobered right up.  So this brings me to ask you via poll;  
HOW OFTEN DO YOU CALIBRATE THE IMU on your drone?

And please feel free to share any additional comments below.

Point place Ohio?

Sunny D Posted at 2017-9-22 18:06
Point place Ohio?

Yup.  Wow, you've heard of it?

I only do it when it is needed

With the pro+ the controller came up with a warning telling me it would be a good idea to calibrate IMU so like a good little boy I did, also calibrated the compass.

when it drifts in hover,app tells you to,or flies funny .

repairman Posted at 2017-9-22 18:46
when it drifts in hover,app tells you to,or flies funny .

LOL, I call it "flying drunk" because... well... I come from a long line of Irish heritage and it reminds me of several of my relatives any given evening.

You probably need to add in the option for calibrating only when the app requires it.

Did it once before maiden flight, no need to mess with it unless clearly required by Go app. Same approach with compass.

Just for something completely different, you could have provided an option which matches how often the manual recommends recalibrating the IMU.

I have never recalibrate the IMU and the program has never requested that I do.  I am not aware of anything in the manual that instructs people to calibrate either the compass or IMU when the drone is used for the first time but read that some did it when they first started using the drone.  I have calibrated compass once when the software asked me to.  

I am confused on the proper use of recalibration for both the IMU and the Compass.  I believe that the manual indicates that you should only calibrate when prompted to do so but I have read posts from both users and administrators on this site that they do it more frequently and as often as prior to each flight.

What is DJI's official position on recalibration?  Do I follow the DJI manual or the instruction given by their representatives and users on this site.  There does not seem to be any consensus from either users or DJI on a "Best Practice".

Capt Whitefoot Posted at 2017-9-22 18:30
Yup.  Wow, you've heard of it?

Heck, I can top that… I was born in Point Place!

Kansas Boy Posted at 2017-9-23 07:22
I have never recalibrate the IMU and the program has never requested that I do.  I am not aware of anything in the manual that instructs people to calibrate either the compass or IMU when the drone is used for the first time but read that some did it when they first started using the drone.  I have calibrated compass once when the software asked me to.  

I am confused on the proper use of recalibration for both the IMU and the Compass.  I believe that the manual indicates that you should only calibrate when prompted to do so but I have read posts from both users and administrators on this site that they do it more frequently and as often as prior to each flight.

Go app displays the state of IMU and compass sensors readings. Good means good, no need for intervention. Bad means bad, therefore related system need to be calibrated. Older DJI drones like P3 or Inspire 1 may need calibration performed more frequently when readings go off acceptable values. New generation sports more robust and reliable IMU and compass circuitry. Apparently OAS need calibration more often (when signalled by app), but that's different issue.

Simple like that.  

Dobmatt Posted at 2017-9-23 10:55
Go app displays the state of IMU and compass sensors readings. Good means good, no need for intervention. Bad means bad, therefore related system need to be calibrated. Older DJI drones like P3 or Inspire 1 may need calibration performed more frequently when readings go off acceptable values. New generation sports more robust and reliable IMU and compass circuitry. Apparently OAS need calibration more often (when signalled by app), but that's different issue.

Simple like that.

Thanks.  I appreciate your response.

A quad can't hover tilted unless there are opposing forces holding it in place. Wind is the obvious one.
When it tilts to one side it will move in the direction of tilt. If the IMU recognises the tilt it will increase power to the lower props, levelling the phantom. If not, it will continue to move in the direction of tilt.

PaulSouthport Posted at 2017-9-23 13:09
A quad can't hover tilted unless there are opposing forces holding it in place. Wind is the obvious one.
When it tilts to one side it will move in the direction of tilt. If the IMU recognises the tilt it will increase power to the lower props, levelling the phantom. If not, it will continue to move in the direction of tilt.

Thats not what mine was doing.  It was leaning to one side yet staying in place thus the reason I said it looked "drunk".  the IMU calibrate sobered it right up.

Kansas Boy Posted at 2017-9-23 07:22
I have never recalibrate the IMU and the program has never requested that I do.  I am not aware of anything in the manual that instructs people to calibrate either the compass or IMU when the drone is used for the first time but read that some did it when they first started using the drone.  I have calibrated compass once when the software asked me to.  

I am confused on the proper use of recalibration for both the IMU and the Compass.  I believe that the manual indicates that you should only calibrate when prompted to do so but I have read posts from both users and administrators on this site that they do it more frequently and as often as prior to each flight.

You've read the manual (which many others fail to do) and have seen what DJI's official position is.
The confusion comes from poor wording in the manuals for earlier Phantoms.
You can safely ignore the folks that want to make up their own rules and procedures.
Your Phantom will continue to fly just fine.

And if you think your app is telling you to recalibrate the compass ....
Don't recalibrate the compass.
Try moving away from whatever it is that has upset the compass.
That will almost certainly fix the problem but recalibrating within the magnetic influence it's warning you about could cause bigger problems.

Labroides Posted at 2017-9-23 15:21
You've read the manual (which many others fail to do) and have seen what DJI's official position is.
The confusion comes from poor wording in the manuals for earlier Phantoms.
You can safely ignore the folks that want to make up their own rules and procedures.

Thanks for the reply.  The one time that I did recalibrate the compass a dialog box opened in GO 4 and told me to calibrate the compass.  It was in an area that was wide open with no trees or buildings structures of any kind for miles (Great Plains of Kansas).  I have flown there several times and never had the problem before or after in that place.  Are you saying that if the program says to recalibrate the compass I should not do it or that I should not do it without first moving to another location to see if the problem persists?  Thanks in advance for the clarification.  

Kansas Boy Posted at 2017-9-23 15:32
Thanks for the reply.  The one time that I did recalibrate the compass a dialog box opened in GO 4 and told me to calibrate the compass.  It was in an area that was wide open with no trees or buildings structures of any kind for miles (Great Plains of Kansas).  I have flown there several times and never had the problem before or after in that place.  Are you saying that if the program says to recalibrate the compass I should not do it or that I should not do it without first moving to another location to see if the problem persists?  Thanks in advance for the clarification.

The most common cause is that a user has their Phantom close to a lot of steel (especially reinforced concrete) or electrical cables.
Moving away is the first thing to try and most of the time, that's all that's required.

Labroides Posted at 2017-9-23 15:41
The most common cause is that a user has their Phantom close to a lot of steel (especially reinforced concrete) or electrical cables.
Moving away is the first thing to try and most of the time, that's all that's required.

I have had a warning once in another place while setting on a metal patio table.  When i moved the aircraft away from the table it went away so i was aware at the time that it could be caused by the surroundings.  My logic at the time was that there should not be anything like that in a wheat field so I went ahead and did the calibration.

I agree with your thought on the issue.  Seems logical that the first thing to try is to move the aircraft away from the location that the error occurred to see if it clears the warning before recalibrating the compass.  I will make that a part of my preflight check process if I get that error again at startup.

Thanks again for the response.

Capt Whitefoot Posted at 2017-9-23 14:44
Thats not what mine was doing.  It was leaning to one side yet staying in place thus the reason I said it looked "drunk".  the IMU calibrate sobered it right up.

I appreciate that it may have appeared that way, but physics says otherwise.

Appearances can be deceptive.

Labroides Posted at 2017-9-23 15:41
The most common cause is that a user has their Phantom close to a lot of steel (especially reinforced concrete) or electrical cables.
Moving away is the first thing to try and most of the time, that's all that's required.

hi labroides,how close can you be to metal buildings to calibrate compass.i have a couple close by?

repairman Posted at 2017-9-24 01:10
hi labroides,how close can you be to metal buildings to calibrate compass.i have a couple close by?

It's a combination of how big their magnetic influence is and how far away.
I wouldn't be launching of calibrating the compass anywhere close to a steel shed.
But then again, I haven't calibrated the compass (or anything else) of the P4 pro that I've been flying hard since December.
For launching, I'd want to be more than 15 metres away.

Kansas Boy Posted at 2017-9-23 07:22
I have never recalibrate the IMU and the program has never requested that I do.  I am not aware of anything in the manual that instructs people to calibrate either the compass or IMU when the drone is used for the first time but read that some did it when they first started using the drone.  I have calibrated compass once when the software asked me to.  

I am confused on the proper use of recalibration for both the IMU and the Compass.  I believe that the manual indicates that you should only calibrate when prompted to do so but I have read posts from both users and administrators on this site that they do it more frequently and as often as prior to each flight.

Generally, the calibration should be done when the APP prompted. I would recommend to calibrate IMU when the drone drift without wind to see whether it helps.

Labroides Posted at 2017-9-24 01:13
It's a combination of how big their magnetic influence is and how far away.
I wouldn't be launching of calibrating the compass anywhere close to a steel shed.
But then again, I haven't calibrated the compass (or anything else) of the P4 pro that I've been flying hard since December.

i,m about 100ft. from 2 metal buildings.i havent had any problems yet. thanks for the reply.

Kansas Boy Posted at 2017-9-23 07:22
I have never recalibrate the IMU and the program has never requested that I do.  I am not aware of anything in the manual that instructs people to calibrate either the compass or IMU when the drone is used for the first time but read that some did it when they first started using the drone.  I have calibrated compass once when the software asked me to.  

I am confused on the proper use of recalibration for both the IMU and the Compass.  I believe that the manual indicates that you should only calibrate when prompted to do so but I have read posts from both users and administrators on this site that they do it more frequently and as often as prior to each flight.

"If it ain't broken, don't fix it !"

Kansas Boy Posted at 2017-9-23 15:55
I have had a warning once in another place while setting on a metal patio table.  When i moved the aircraft away from the table it went away so i was aware at the time that it could be caused by the surroundings.  My logic at the time was that there should not be anything like that in a wheat field so I went ahead and did the calibration.

I agree with your thought on the issue.  Seems logical that the first thing to try is to move the aircraft away from the location that the error occurred to see if it clears the warning before recalibrating the compass.  I will make that a part of my preflight check process if I get that error again at startup.

You will find that most crashes around here start with the opening line.

I just calibrated my compass, or everything was calibrated before I took off.

One thing is for sure you can’t make an already good compass any better by calibration , but you can sure make it worse.

IMU "Inertial measurement unit" .

As far as I see it, IMU calibration on a level surface updates a table of values the flight controller software uses as a reference for a level stationary hover. From there the craft responds predictably to flight commands.  It also likely measures any sensor noise and thermal drift so that these technical imperfections are accounted for when using IMU sensor data in flight. - this is likely why there must be no vibrations during the calibration process.


Bad IMU calibration could cause drift and attitude issues as the flight controller fights to hold the craft in what it thinks is the correct attitude as opposed to the correct physical attitude.


The IMU usually has 2 types of sensors – angle and acceleration and in turn 3 sensors of each type measuring in the X,Y and Z axis. These sensors can, through vibration, aging, impact etc, drift in their response over time and thus an IMU calibration will establish a new reference for the IMU’s level/stationary state that the flight controller can work with to restore stable flight.


Think of calibration as the bringing back into line the measured craft attitude with the true physical craft attitude.


As to how often an IMU calibration is needed, Refer to your manual ; Remember calibration won’t make a good IMU any better, but often can make it a whole lot worse.

When its required, normally after a software update, or when the drone prompts me to do it.

SPIKE_151 Posted at 2017-9-26 02:30
When its required, normally after a software update, or when the drone prompts me to do it.

After a software update?
What page of the manual is that from?

Labroides Posted at 2017-9-26 03:13
After a software update?
What page of the manual is that from?

its not from the manual , but after some updates I have been prompted to recalibrate

I'd say when the App requires it or after a crash if the App doesn't prompt you at that point.

never did. Still flies rock solid...

Antonio76 Posted at 2017-10-8 09:19
never did. Still flies rock solid...

LOL, you apparently haven't  done any tree trimming with yours or anything.  That's great to hear.  

Capt Whitefoot Posted at 2017-10-8 17:49
LOL, you apparently haven't  done any tree trimming with yours or anything.  That's great to hear.

No tree trimming. Actually I flew around and made a video when we had the birches at the sides of the road trimmed, but chainsaws were used.

after every firmware update

Bino Posted at 2017-10-11 03:47
after every firmware update

Are you flying in a cardboard box?

Yes cleaned the leaves off my sisters roof

Titanbot 4 Posted at 2017-10-12 15:33
Yes cleaned the leaves off my sisters roof

I always use it to blow the grass from the sidewalks and driveways after mowing.  Who says its just a "toy"???

Right, wish i still had vid of leaf  cleaning.  Helps with narrow control and low flying