m80116
Captain
Flight distance : 3264131 ft
Italy
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Like many of you I've noticed that oftentimes the not the (OD) Orientation Dial (as defined by the user manual) at the centre bottom part of the Fly app and representing the aircraft (AC) with an arrow relative to the pilot is out of sight or pointing in the wrong direction than where the drone is actually heading.
The AO dial is in reality a double orientation dial, although with a fixed view.
The Aircraft is represented by the pointed arrow and relies on the position and orientation which is trasmitted by the aircraft itself. As long as your AC compass is calibrated and initialized (powered on) in a non-distorted magnetic field (i.e. having a normal Earth magnetic field), the heading provided is always correct. But which direction is right? Things get tricky here...
The user heading is a fixed big dot with a conic view, that never changes (since you're not supposed to wield the RC sideways or upside down). What changes is the placament of the AC on the half dial infront of the user (when it's in front) and the orientation of its arrow representing indicator, thus for the AC arrow to be correctly placed and oriented on the disc, the DJI Fly app must receive the correct user heading from the Mobile Device (MD). Here lies the uppermost problem of wrong compass heading indication.
Unfortunately most MDs are deeply affected by the Remote Control (RC) proximity and even when the Fly app has been the one initilizing the magnetic field sensor, the orientation is still wrong until that sensor is calibrated for the new varied magnetic field while the RC as attached.
After several field tests I've found and verified a quick way to properly calibrate the compass, without leaving the DJI Fly app and only requiring a few arm/hand motions. Google didn't lie in their compass calibration screen within the Maps application, and that's exactly what I am using. Other kind of rotations don't calibrate the compass although it seems after a while to slowly go into the correct heading... but waiting 15 minutes to get proper heading isn't really a solution, the MD needs to be put into calibration mode to rapidly acquire the correct heading.
How to properly calibrate the compass on your Mobile Device
The Google way: to properly and quickly calibrate the MD all it takes is to follow Goog's own directions, without even leaving the Fly app. I've personally tested this gesture with my right hand and verified working every time. Bring the MD/RC assembly at your torso height, orient the screen as if you were taking a phone call and start waving the MD/RC assembly in a transverse figure of 8 motion. Imagine an 8 that's skewed to the left top to bottom and follow along that line as if you were drawing it (see attached animated gif). Do the circle of 8 for 3 times. This method manages to bring the correct heading in seconds beucase I feel is that particular motion that's triggering the calibration of the magnetometer inside the MD, it has been proved to work with Android 9 and 10 in my Samsung G965F/DS (S9+).
After a correct heading (compass) service is established on the MD one can correctly see the AC arrow pointing the right direction relative to the pilot position although it must be noticed with a certain degree of approximation. You still cannot pretend of being 1 meter behind the aircraft and see it every time ahead of you on the orientation dial, but in an open and empty field you can certainly verify walking around the aircraft brings slow and steady changes of the AC in position and heading around the half OD disc. For example keeping a distance of about 10+ meters from the AC as you walk around from infront to the back of the AC passing from the starboard (R) side you can notice the arrow appearing in the bottom left side of the disc and gradually moving up as you approach the center behind the AC, the heading of the arrow will closely follow your orientation. So if you stop at a 135° from N AC heading (South East of the AC) and watch N inline with the drone you'll notice the AC arrow half-way left in the AO dial, exactly aligned with you. Let's say you change your heading looking at the AC you'll notice the AC arrow changing orientation and sligthly facing you. The AC heading on the Fly app is accurate only when the correct calibration of your MD compass attached to the Remote Control has been accomplished.
Please remember: an uncalibrated MD doesn't cause any major problem, you can still navigate the AC using the bottom left map to bring back your drone should you lose visual cues. But a distorted compass on the AC can lead to drone loss and major accidents. Be very careful to always calibrate the AC compass when requested and never power on the AC in close proximity of reinforced concrete structures, flooring, bridges, power lines, metal railing and if you do, please keep a close eye on the AC arrow heading, should it shift while you take off and elevate or move away from the home point erraticaly be ready to take action immediately, bring your drone down before even trying to counter any drift tendency and land as soon as possible.
Good flights and happy landings!
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