Mavic air compass calibration every flight? Here’s why…

I have owned the DJI Mavic air for approximately two years. I absolutely love this drone because it is the perfect combination of quality and feature-packed hardware combined with a small form factor which means that I don’t mind carrying my drone nearly everywhere I go. There are so many things to love but the one thing that many people have experienced is that the DJI Mavic air requires a calibration each time you start it up. I have experienced it recently and it seems that every single flight I do requires me to spin around in circles to calibrate the compass. In this article, we are going to look at all of the reasons why the Mavic air compass needs calibration on nearly every flight and what you can do about it so that it doesn’t happen as often.

The Mavic air compass needs calibrating often. This could be due to changing a location, changing your altitude, interference from metal objects, a firmware update, your smart watch (with a magnet) or a combination of the above. It may be frustrating but calibrating your drone is one of the best ways to keep it safe and secure while you are flying.

When you first turn on your drone you will see that it has a red error and informs you that it cannot take off and that you need to calibrate your compass. Calibrating your compass relies on you spinning the drone around two axes a few times. This normally takes less than one minute but with the DJI Mavic air having a 15 minute flight time it can be frustrating that it is taking off a fraction of your enjoyment.

The reasons you need to calibrate your drone every time!

You may find that you don’t have to do calibrate your drone every single time but many people have had this experience. Perhaps you are noticing that you need to calibrate your Mavic air more often than other drones you have owned. There is a little bit of a confusion about whether or not the Mavic air contains two compasses. It only has one compass but it does use a visual navigation system to make sure that is heading in the right direction which acts kind of like a compass. Let’s talk about that first.

The Mavic Air has a “vision compass”.

There are a few forums online that talk about the Mavic air having two compasses. I think this is a misunderstanding of some of the technical features of the DJI Mavic air drone. There is only one compass. However, DJI have marketed this drone as having multiple redundancies. It has dual inertial measurement units but only one compass. The other compass is known as a vision compass which assists the navigation system to estimate the flight direction if the compass experience is any significant interference during your flight. This is what the DJI marketing blurb says:

“Besides dual IMUs, FlightAutonomy 2.0 has more redundant modules to increase the Mavic Air’s safety level. The Vision Compass will assist the navigation system to estimate flight direction when the compass experiences interference. When only one direction of the front, bottom, or rear vision systems is functioning normally, the aircraft will still position itself successfully. There are two sets of sensor fusion algorithms based on two independent hardware platforms. When an error occurs to one set of algorithms, the aircraft will switch to the other pair seamlessly to resume normal functionality.”

Now that this misunderstanding is out of the way here are some of the few reasons why your drone compass may need calibrating each and every time you start it up.

Changing location

Changing the location of your drone more than a kilometre, or so, may indicate to the drone that you are in a completely different location and as a safety precaution, the drone asks you to calibrate your drone. I have done numerous trips with my drone where it has been sat in the back of a car and taken out many hundreds of kilometres away from where it started.

For example, I recently went on a three-week road trip where I was covering at least 500 km per day. There wasn’t a day that didn’t go by when my drone didn’t need another calibration. Perhaps in the starter series of the drone when it is checking the GPS location the massive change in location prompts a calibration message.

Changing altitude

Not only does changing location matter but I believe that changing altitude significantly also impacts the drones compass calibration. Sometimes, after I have climbed a mountain the drone will ask me to recalibrate the compass. I have done this on a number of significant walks in the national parks around Australia and found that changing altitude and location always results in the notification to calibrate my drone compass.

I always see these messages as a positive sense I would rather have my drone prompt more often and have it returned safely than for it to assume something which would put itself in harms way.

Interference from metal objects

Another aspect that is very important when the drone is taking off is when you are trying to take off from an area with significant metal infrastructure. For example, I always look for a flat concrete area to take off on. If this is a path there is not normally too much of an issue. However, I find that sometimes the concrete area has metal reinforcement in the concrete and therefore I get a compass error and a prompt to recalibrate.

If you are finding that your typical takeoff spots are always requiring you to recalibrate your compass you should try moving your drone takeoff point to a different area. Buying a landing pad for your drone means that you can take off on sand, grass, and other areas that contain loose surface debris. If you want to know more about landing pads check out my other article – do I need a landing pad for my drone? A complete guide to drone landing pads – click here to be taken to article.

Do I need a landing pad for my drone

Firmware update

Sometimes, your drone will ask you to update the firmware of the drone or remote or update the app. Firmware updates on important thing to do as they provide you with different security patches and continue to introduce new features to your drone.

The issue is that sometimes a firmware update can introduce more bugs than it solves. Or maybe it’s not that it introduces more bugs but rather that it introduces worse bugs than you had before. If you have recently updated your firmware it is a good idea to turn on your drone at home before going out and do all the important calibrations that it asks you to do.

Update your SD card

This may seem like a strange one but if you are having this issue and it is frustrating you then this is something you should consider. Many people have found that there is a strange interplay between the SD card and some of the drones features and functions.

The DJI Mavic air, and other DJI drones, have about 8 GB of internal memory. So, if you find that this is happening often to you you can simply remove the SD card to see if the issue goes away. Some people on the forums have reported that updating their SD card or changing the brand of the SD card and making sure they don’t have a counterfeit one has helped them in a number of different calibration issues.

All you have to do for this is remove the SD card and take note of how often it happens. If you have noticed a significant increase after removing the SD card from the drone while it is starting up you should consider purchasing a new SD card to see if that alleviates key issue. I think this is a smaller proportion of drones but still worth trying if nothing else has worked for you

Move away from wires

Not only do metallic objects affect the drones ability to calibrate the compass but overhead wires and noisy industrial or urban areas can also produce a significant amount of magnetic interference.

Your area may look like it is relatively opening clear but if you look up is there a significant amount of wires only a few hundred metres away? Sometimes we launch our drones in what we think is a completely clear area only to find that they still a lot of interference. This could be coming from overhead wires or underground cabling.

It can be frustrating but by simply calibrating your compass you can normally get on your way.

Turn drone on away from objects

Where do you normally start up your drone? Some people start up their drone in their car before heading out and placing on the ground. As soon as you turn on your drone it starts at start-up sequence and if it is registering that the compass is weak because you are inside a huge metal object it may be prompting you because of that.

I recommend that if you have any calibration or things to do for your drone flight you should do it at home away from metallic objects and then use a fresh battery for when you turn up on site. If you cannot do this you should consider leaving the car before turning on the drone and making sure the drone is taking off from at least a couple hundred metres away from any metallic objects which includes your car.

A Mavic owner tried to create compass interference by bringing his belt buckle, keys, and other personal effects close to the drone. It was only when the phone is a speaker was on top of the drone that there was significant interference. They note that the only consistent way to produce interference was to place a pocketknife on top of the battery compartment. So you don’t need to be too worried about having any metallic objects in your pocket or near the drone during takeoff.

To check that your calibration is good all you have to do is take off and do some yawing at an altitude of about 10 m. Check your screen and see if the movements correspond with the direction that the drone is being yawed.  This simple check is something that will save you a lot of headaches if you are worried about compass miscalibration.

Apple or other smart watch

What do you wear when you are turning on your drone? Some people have noticed that if they are wearing an Apple watch which has a magnet included in the design their drone is more likely to ask for a calibration upon start-up. This is because the magnetic component in the device is interfering with the magnetic components of the drone.

If you have a smart watch I recommend leaving it behind for example in your car if you are going to fly your drone. Other smart watches may not have the inclusion of a magnet and so it will not affect the calibration of the drone.

Maybe you need to send it back for repair!

Lastly, there are some things that these simple tricks just cannot solve. If you find that your compass issue is so severe and that he is severely limiting your enjoyment of your drone then the last option you have is to send it back for repair.

If your drone is unable to be calibrated or it is having persistent issues of losing calibration when it is flying this is a serious issue that you need to bring up with the DJI support team. My understanding and experience with dealing with the support team is that they are very understanding and will very quickly help you overcome any issues.

Sending your drone for repair will result in it being repaired by a professional or in some cases they send back a completely new drone. In the worst cases some people have found that they need to go through three or call drones but this is rare and it is often solved quickly.

 

How do I calibrate my DJI Mavic Air compass?

Calibrating your DJI Mavic air compass is relatively easy. You need to rotate the drone around two axes and it’s as simple as following the on-screen instructions:

  • firstly, you will hold the drone in its flying position and rotate around the vertical plane.
  • Secondly, you will point the camera to the ground and spin the camera while keeping the camera fixed in the same location.

Once you have gone through these two procedures the drone will be calibrated and ready to use. If you find that the calibration needs to be repeated or that it still doesn’t work after attempting a number of times you should move to a different location as there may be significant interference from metallic objects in the close vicinity.

Mavic air compass calibration every flight

How often should I calibrate my drone?

You should calibrate your drone as often as required to keep it flying safely. This means that you should calibrate certain aspects of your drone when the software is prompting you to. Quite often, with drone manufacturers you cannot actually fly your drone until you have calibrated all of the sensors which have a warning notification against them.

You should also consider calibrating your drone if you notice any of the following or your drone has been subject to any of these:

  • if you notice your drone is drifting significantly while flying you may need to recalibrate the compass to provide stability.
  • When you hit the automatic land and return to home function and your drone flies the wrong way you need to recalibrate the GPS and compass immediately.
  • If you notice that your drone does not hold its altitude very well you will need to recalibrate your inertial measurement unit so the barometer can function properly.
  • If you have moved a significant distance since your last flight you may find that your compass will need to be recalibrated.
  • You need to recalibrate your drone after every significant impact or crash (as long as the drone is not damaged beyond repair).
  • After a significant time in transit. I have found that during a long car journey or a significant plane journey my drone needs to be recalibrated and will prompt for it. The differences in temperature that are experienced during a road trip combined with the constant vibration of travel can confuse the accelerometer.

Summary

Calibrating your drone can be sometimes very frustrating. Especially if you perceive it as taking away some of your flight time. However, a reframing of this issue will allow you to appreciate that the drone is just trying to fly as safe as possible. Advanced flying features like GPS location and return to home rely heavily on the drone’s compass. If the drone experiences any significant issues with these components it can easily cause a flyaway which is devastating for the drone and the owner.

I never mind taking the extra few minutes to calibrate my drone if the hardware is telling me to do so. If your calibration issues persist you should get in contact with the DJI support team for a replacement or repair.

The Author

Dr Andrew Stapleton is a writer and YouTuber with a PhD in science. He has written and/or produced videos for Science Alert, COSMOS magazine, and Australia's Science Channel among others. Andy started droneflyingpro.com to share his love and the research of all things drone! He has been a drone pilot for many years and has flown many types of drone. His favorite is still the DJI Mavic Air for the portability and functionality packed into a small and portable drone!