Aardvark
Captain
Flight distance : 384432 ft
United Kingdom
Offline
|
Sky Chief Posted at 6-27 16:43
I see others have had the same issue. Some replies suggested the compass should not be calibrated if the app does not instruct to. One tutorial I saw suggested calibrating often. I'm new to this, so not sure what to do. If the devices were calibrated in China, and I'm in California, it would seem logical to re-calibrate. ???
That 'compass button' you are looking for is normally just a shortcut to the compass calibration routine within DJI Go 4, which can be found by navigating through the menus. I seem to remember there was one iteration of software where that could only be seen if the system requested calibration.
I would not calibrate the compass if the system does not request it. It should rarely, if ever, need to be redone.
I believe the compass calibration is not specifically to allow for changes as you move about the planet. What it does do however is check what allowance it needs to make in it's calculation for ferrous metals in the immediate vicinity of the compass. Basically anything which is part of the aircraft (or added), and the effects that might have on its reading of the Earths magnetic field. To all intents and purposes, for our short flights, magnetic North shouldn't change significantly enough to have much bearing at all on the flight.
What can happen however, and the risk is relatively high, is that a compass can be 'wrongly' calibrated. The aircraft has been close to some very localised ferrous object or magnetic interference (iron car parts, buried pipework, steel reinforced concrete, power lines etc) when calibration done.
This means that any offset added to the compass after calibration is completely wrong. The reading from the GPS when the aircraft starts moving gives it a 'rough' idea of which direction it's travelling. If the compass reading is significantly different then there is a conflict between the data, this conflict will cause the aircraft to switch to 'ATTI mode' (attitude mode, where the aircrafts attitude will remain level, but it will not be able to keep position relative to ground and will drift with the wind).
It seems that in error, or by design, the newer software can request calibration more often than was the case in the past.
If the compass says 'Normal' then all is well, no calibration is needed.
That's my take on it anyway, and I believe it to be correct :-)
|
|