Drone calibration is a very important part of owning a drone. Not only does it protect your drone from accidents but it can help you produce smoother video and keep everything running smoothly. Quite often, drone software will remind you to calibrate certain aspects of your drone hardware such as the compass but other times you need to calibrate certain aspects of the drone when faced with a particular issue such as drones drifting or flying away. In this article we are going to go over everything you need to know about calibrating your drone and why it is so important to do regularly.
Why do I have to calibrate my drone? You have to calibrate your drone in a variety of ways to ensure that its sensors will provide accurate information to the software which is keeping your drone flying in a stable and safe manner. Throughout a regular flight your drone can undergo a variety of physical actions such as vibration, and collision incidents which can throw off the calibration of your drone components.
Calibrating a drone or a drone controller is the process of setting and correcting the errors which exist because the sensor is not picking up an accurate representation of the real world. Calibration is the act of making sure the data sent to the drones computer is a true representation of what it is experiencing. Any small differences between the data sent to the controller versus what is really happening can result in an incredibly dangerous and unstable flight.
But how often should you calibrate your drone and how exactly do you do it? In the next section, we are going to answer these questions.
Do you have to calibrate a drone every time?
It is unlikely that you have to calibrate your drone every single time. Drones have an internal memory which will remember some of the best settings that often are set at the manufacturing stage. However, in popular drone models such as the DJI Mavic series you are prompted by the GO4 app to calibrate certain aspects when it is required.
When you first receive your drone it is likely that you will be asked or prompted to calibrate certain aspects of the drone when setting up for your first flight. This can include but is not limited to sensors such as:
- The compass
- The inertial measurement unit consisting of:
- the thermometer
- the gyroscope
- a barometer
- the accelerometer
- Geomagnetic calibration
Depending on the drone that you have purchased and the advanced software features that it has for example, auto stabilisation, auto hover, altitude hold, and other flight assistance software this calibration could be an important component for you to achieve a stable and safe flight.
Some drones require you to calibrate the compass every time you set up your drone. This is typically so that the GPS can track your drone and it will be able to return to home and land automatically should there be an issue throughout your flight.
A rule of thumb for all drone flyers is that as soon as your drone is an airborne you should hover at about 3 to 5 m and is just check in with the stability and make sure that it performs exactly the way you expect it to. If it does not, you should land the drone and recalibrate the compass and anything else that has had a recent warning alert.
Doing this simple cheque only takes a matter of seconds but can save you from losing an expensive gadget to a silly miscalibration error.
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.
How to calibrate a drone
There are a few aspects of calibrating a drone which you only have to do every so often. This includes the accelerometers, IMU and the compass. Here will go over how you calibrate each one and tell you the best ways to do it.
Accelerometer’s are present in every drone and they play a very important part in determining the stability of the drones flight.
Accelerometers measure the rate of change of movement. So, if you hold the drone still the sensor will not pick up any changes of movement no matter where the drone is situated.
Each drone is calibrated slightly differently due to the software differences as well as the hardware that each drone contains but all of them follow the simple basic steps whilst calibrating the accelerometer.
- Make sure the drone is held in the same orientation as indicated by the software that you are using to calibrate the accelerometer.
- Place the drone on a flat and stable surface and it is not moving.
- Initiate the software calibration procedure for your drone.
- Some require the drone to be powered off and on again. Follow all instructions on the software.
Here are some common drone models with a link to the best calibration methods that I have found.
|Drone Model||Link to the calibration method|
|DJI Mavic Mini||Youtube Link|
|DJI Mavic Air||Youtube Link|
|Parrot Anafi||Youtube Link|
|Syma X20 Mini Drone||Official YouTube|
|DJI Phantom 4 Pro+||Official Youtube|
There are also many scientific research groups which are looking at making drone accelerometer calibration more accurate. One such study published in 2018, shows that they are able to increase the accuracy of the accelerometer simply by running the calibration data through a different series of mathematical filters. So, this fills me with hope that accelerometer calibration will get easier and faster and more accurate in the near future.
The compass on a drone is very important. It is the one thing that drone software asked you to calibrate often. This is because the drone compass is the failsafe for your drone returning to home if something goes wrong during the flight. If your compass is miscalibrated your drone can very easily go off in the wrong direction and you may never see it again.
To understand completely why drone flyaways happen check out my other article – why did my drone flyway? [And what you can do about it] – click here.
There are many reasons why a drone compass may become miscalibrated and it is mainly due to its proximity to large metallic or magnetic objects.
In the DJI GO4 app you can see the interference by going to settings> advanced> compass and look at the interference indicator. You will be able to do your own seeing the interference indicator increase as you bring your drone to magnetically charged objects.
You may be surprised at how little it really does change but there are some things that will cause it to move a lot. In my experience the biggest issue is reinforced concrete. I like to take off on flat surfaces and I often find flat concrete surfaces to take off from however the iron reinforcement on the inside of the concrete causes significant Compass interference.
As a rule of thumb you should stay away from:
- power lines
- huge metal deposits like junkyards
- any large metallic structure such as sheds
- any large speakers – they have magnets on the inside
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.
The inertial measurement unit is a device that is built into your drone and contains a load of different sensors to keep the drone running properly. Specifically, it measures the force, altitude, and angular velocity of the drone during its flight. These are measured through a series of different sensors that combine for a very powerful unit.
The sensors that it includes are the accelerometer, gyroscope, barometer, and thermometer. The gyroscope is a sensor that will detect the drones movements relative to the horizon level and it will be responsible for retaining the stability so that you can get some awesomely smooth shots that will not come out blurry. The barometer is used for detecting the changes in the height of the drone. And I think everyone knows what a thermometer is – it measures the temperature of the drone to make sure that the batteries do not overheat and start a fire.
Drone manufacturers are making the inertial measurement unit incredibly easy to calibrate. It should only take you about five minutes to do a complete calibration. All you need is an area that is sitting level and is stationary while you are calibrating the IMU.
This is what you need to do for a DJI manufactured drone:
- lay the drone down on a completely flat surface.
- Allowing the drone to cool down if it has recently been flown.
- Use a battery that is more than 50% charged.
- Open up the GO4 app.
- Turn on the controller for the drone
- navigate towards the advanced settings in the GO4 app and follow the calibration instructions.
The process for calibrating a mid range consumer drone varies from a mini drone. This is because a mini drone does not contain the same level of hardware to keep it stable during flight. Instead, it relies on something called “trimming” to keep it flying stable.
How to calibrate a mini drone
Calibrating a mini drone is different to calibrating a consumer level drone from a manufacturer such as DJI. A drone from the mid range of drones requires all of the above hardware to be calibrated properly. Quite simply, a mini drone does not come with all of these different types of sensors.
A mini drone can only fly properly if the propellers and motors are manually calibrated. This means flying the drone in a wind free environment such as a living room or well sheltered back garden and trimming the propellers until it flies in a stable way. You will still need to manually adjust its position to keep it in a fixed spot but the drone should not drift significantly when you take your hands off the controls.
To trim a mini drone the drone will need to be flying while you are doing it. Use the trim buttons on the mini drone controller to adjust the propellers to keep the drone stable.
Depending on the manufacturer the drone may have two sets of arrow buttons or trim buttons as well as a your trim which is used to stop the drone from spinning in either a clockwise or anticlockwise direction.
Essentially, you will be using these buttons or wheels to counteract the natural movement of the drone. For example, if your drone drifts to the left you should push and release the right side of the trim button in till the drone no longer moves to the left.
Complete this process for left, right, spinning, forwards and backwards. It may take you a few times to get this trimming perfect but it will be worth the hassle since your flying will be much more enjoyable if you are able to control the drone with ease.
If your mini drone undergoes a significant crash, you will need to re-do the trimming as the shape of the propellers and the efficiency of the motors may have been affected by the crash.
Common drone calibration issues
There are some common drone calibration issues that you will encounter no matter what the make or model of the drone. Here will go through how you can tackle some of the most common issues that are due to miss calibration.
Always having to calibrate the compass
One thing that I always notice when I fly my DJI Mavic air is that I need to calibrate the compass nearly every time. Other people have also noted that whatever they fly their drone after a long journey it requires them to recalibrate the compass.
It isn’t necessarily a hard thing. All you have to do is pick up the drone and spin it around in a clockwise direction and then point the nose down and spin it in the same way. It takes me less than one minute to complete the calibration but it is a little bit frustrating that I have to do the recalibration each time I fly the drone.
Depending on how you use your drone you may not have to calibrate the compass in between each flight. Some drone experts say that doing a calibration before each flight just because it raises the issue of getting a bad calibration. They find that if you have a good calibration and there is no need to do it again.
Drone is drifting
if your drone is drifting it can be caused by a few issues that you can calibrate out of your drone. There are a few common culprits of drones drifting. Here are the seven that could be causing this issue:
- Accelerometers need calibrating
- Transmitter settings
- Motor or ESC problems
- Propeller issues
- Not in GPS mode
- Backing up from obstructions
- Balance and placement of components
Make sure that you do a full calibration of the IMU as well as checking software and hardware issues and check out my other article for a full run down on how to do that – click here.
Calibrating your drone is a very important part of drone ownership. It keeps your drone safe and secure law while flying and also provides a reliable failsafe if something was to go wrong during the flight.
Take calibrating your drone seriously and I can guarantee that the couple of minutes you take will pay off in image quality and a much more stable and enjoyable flight.