Atti Mode

[Meta4]

Yea, I thought that might be your consensus. Though there are numerous horror stories in the forum where pilots had wished they'd performed a calibration prior to flying, as it might have prevented an compass and or IMU discrepancy. While I understand both the pros and cons associated with performing a calibration every time you launch the bird, I'd advocate a performing a calibration if when at boot up you receive an compass error, or are just launching from a new site that hasn't been flown in. Safety first, as Magnetic interference near the takeoff point or un-calibrated compasses are the usual suspects.

It seems you have a poor understanding of what calibrating the compass actually does and this is affecting your thoughts on the matter.
A compass error would be more accurately called a compass warning.
It's not a fault in the compass system that requires correcting.
It's a perfectly functioning compass giving a warning about magnetic fields it has detected nearby.

Calibrating the compass does not adjust the compass and make it more accurate.
Calibrating the compass identifies and measures the magnetic fields that are part of the drone, so they can be ignored allowing the compass to then give accurate compass data, unaffected by onboard magnetic fields.
Once you have done that, there's no need to do it again unless you modify the drone.

The numerous horror stories you refer to where pilots had wished they'd performed a calibration prior to flying, come from a similar lack of understanding.
Unnecessary recalibrating of the compass won't do anything to correct the problem of launching from a magnetically dirty launch point

 

[DanMan32]

In an ATTI mode activation situation, what control options will the aircraft respond to?

Up, down, left, right, forward, backward, yaw left, yaw right.

Gimbal down, gimbal up, start recording, stop recording, take photo.

I would refrain from any photo ops as you'll spend most of your concentration keeping it stable against wind, turbulence, etc.
We get quite spoiled with GPS and VPS holding our aircraft steady.

 

[Rocket Man]

Right, but of those seven examples, only one (Mavic suddenly switched to ATTI mode mid flight) was indicative of a calibration problem, and it's one of only two that I have ever seen reported. And I have analyzed many tens of such events. As I said before, ATTI mode events are almost never due to calibration issues. So if you want to calibrate every flight that's fine, but I am going to continue to point out that the data do not support the need for that.

Asked and answered. In the famous words of Benjamin Franklin “an ounce of prevention is worth a pound of cure”. While I'll conceed that you don't want to get in the habit of overcalibrating the aircraft, As Mossiback eliquently stated, It's worth checking the Go 4 before flying for any notices, and being cognitive of your surrounding area.

 

[Meta4]

In the famous words of Benjamin Franklin “an ounce of prevention is worth a pound of cure”.

That might be relevant if re-calibrating the compass actually prevented something.
But as explained in post #21, the idea that recalibrating prevents undesirable outcomes comes from misunderstanding what calibrating the compass actually does and when it might really be required.

 

[Rocket Man]

Hmnn, I'd have to disagree, that re-calibrating the compass/IMU does not prevent any adverse actions of the Mavic Pro and or Mavic 2 for that matter. The Mavic Pro manual provides specific guidance on when to calibrate / re-calibrate the Mavic Pro, prompted or otherwise. Additional guidance for the Mavic Pro series is also available from various online resources. Implementing these preventative measures prompted or otherwise, will help to ensure safer, more enjoyable flight time.

When to Recalibrate
1. When compass data is abnormal and the Aircraft Status Indicator is blinking green and yellow.
2. When the mechanical or physical structure of the Mavic Pro has been changed.
3. When severe drifting occurs in flight, i.e. Mavic Pro does not fly in straight line.

DJI recommends three instances when the compass should be calibrated on the Mavic 2 series.
1- If you receive a compass interference warning on the DJI GO 4 app or if you notice alternating yellow and red blinking aircraft status indicator lights.
2- If you travel further than 31 miles from the last spot you flew.
3- If it has been more than 30 days since you last flew your Mavic 2.

Mavic 2 Series Compass Calibration: Complete Guide - Let Us Drone

 

[Meta4]

Hmnn, I'd have to disagree, that re-calibrating the compass/IMU does not prevent any adverse actions of the Mavic Pro and or Mavic 2 for that matter.
...
When to Recalibrate
1. When compass data is abnormal and the Aircraft Status Indicator is blinking green and yellow.
2. When the mechanical or physical structure of the Mavic Pro has been changed.
3. When severe drifting occurs in flight, i.e. Mavic Pro does not fly in straight line.

Interesting that you are saying recalibration is a preventative measure but the three examples you provide are all cases where there is a known problem and recalibration might be used as a remedy rather than as a preventative measure.

DJI recommends three instances when the compass should be calibrated on the Mavic 2 series.
1- If you receive a compass interference warning on the DJI GO 4 app or if you notice alternating yellow and red blinking aircraft status indicator lights.
2- If you travel further than 31 miles from the last spot you flew.
3- If it has been more than 30 days since you last flew your Mavic 2.

If DJI had accurate compass information in their manuals, there would be no debate.
Points 1 & 2 refer to factors (distance and time since calibration) that have no influence on compass operation.
Point 3 is quite wrong - If your compass is warning of a problematic magnetic field nearby, recalibrating the compass will not do anything to solve the problem.

But DJI have spread inaccurate information like what you've posted above for years.
They can't even be consistent.
Look at what they say on P57 of the P4 pro manual:
Only calibrate the compass when the DJI GO 4 app or the status indicator prompt you to do so.

Unfortunately DJI English language manuals are not up to the standard of their drones and it's been necessary for users to work out what's right and what isn't.
Their compass calibration section is a prime example and responsible for the myths, misunderstanding and superstition surrounding compass calibration.

 

[sar104]

Asked and answered. In the famous words of Benjamin Franklin “an ounce of prevention is worth a pound of cure”. While I'll conceed that you don't want to get in the habit of overcalibrating the aircraft, As Mossiback eliquently stated, It's worth checking the Go 4 before flying for any notices, and being cognitive of your surrounding area.

Absolutely - you should always check for and pay attention to notices in the app before takeoff. But that's not remotely what you were recommending, or at least what you appeared to be recommending, which was to calibrate the compass and IMU before every flight.

So for "Best Practices", and to minimize ATTI related issues, it would be beneficial to calibrate the IMU / compass prior to flight operations??

 

[Rocket Man]

Interesting that you are saying recalibration is a preventative measure but the three examples you provide are all cases where there is a known problem and recalibration might be used as a remedy rather than as a preventative measure.


If DJI had accurate compass information in their manuals, there would be no debate.
Points 1 & 2 refer to factors (distance and time since calibration) that have no influence on compass operation.
Point 3 is quite wrong - If your compass is warning of a problematic magnetic field nearby, recalibrating the compass will not do anything to solve the problem.

But DJI have spread inaccurate information like what you've posted above for years.
They can't even be consistent.
Look at what they say on P57 of the P4 pro manual:
Only calibrate the compass when the DJI GO 4 app or the status indicator prompt you to do so.

Unfortunately DJI English language manuals are not up to the standard of their drones and it's been necessary for users to work out what's right and what isn't.
Their compass calibration section is a prime example and responsible for the myths, misunderstanding and superstition surrounding compass calibration.

As an end user of the DJI product, I have to take into account the operational information provide in their manual is to technical specifications, after all, they are the SME's. To dismiss the written content, is to throw the baby out with the bath water. If you can't trust what the manufacturer technical guidelines are, albeit the bare minimum, then I guess it's not worth purchasing their product. Though thousands of people have purchased their products, which is an testament to the quality of the product and technical guidelines provided. As with every piece of sophisticated consumer hardware/equipment available on the market, there's room for improvement with software upgrades, technical manual upgrades and quality of customer service. All of which we as end users have a responsibility to inform the manufacturer of any inaccuracies or inconsistencies in their product. Being that you have honed in on a couple of areas where the manufacturer could improve their product, might it be beneficial to put paper to pen, and for the good of the product and all Mavic Pro user's, let the manufacturer in on our little secret, that their manuals are outdated and need to be improved?
Until then, as we have debated and discussed here in this forum, I'll continue to be vigilant in adhering to DJI's Calibration /IMU best practices, while implementing Tips and Tricks learned by others provided in this forum, to ensure proper calibration, safe flight and the minimization of and or reaction to the implementation of ATTI Mode during flight. Fly Safe.

 

[Meta4]

Fly Safe.

The best way to ensure you fly safe, is to properly understand how your drone really works.
Believing and adhering to procedures that have proved to be incorrect is not "best practice".

 

[FoxhallGH]

It's interesting that there have been reported incidents involving 'compass' issues in the forum, which have actually pointed to the compass in the mobile iOS / Android device needing calibration. A pre-flight factor to be wary of, is to check that the little red arrow-head denoting your Drone on the map in the bottom left corner of Go 4, is actually pointing in the same direction that the [physical] drone is ... You'd be surprised how many times it isn't - and how many times it's ignored. Rather than worrying too much about compass calibration on your drone, have a look at the compass calibration steps needed in your iOS / Android mobile - as that's probably just as important to your accurate navigation.

 

[Meta4]

It's interesting that there have been reported incidents involving 'compass' issues in the forum, which have actually pointed to the compass in the mobile iOS / Android device needing calibration. A pre-flight factor to be wary of, is to check that the little red arrow-head denoting your Drone on the map in the bottom left corner of Go 4, is actually pointing in the same direction that the [physical] drone is ... You'd be surprised how many times it isn't - and how many times it's ignored. Rather than worrying too much about compass calibration on your drone, have a look at the compass calibration steps needed in your iOS / Android mobile - as that's probably just as important to your accurate navigation.

The situation you describe doesn't affect the safe navigation of your drone, it just means the orientation of the radar display is wrong.
Home is still in the centre so you could still use it to fly home blind.
I used to fly with a tablet that was the best back in its day .. except the maker fitted 6 powerful magnets inside the case of the tablet.
It was impossible to calibrate the tablet's compass but that was more a minor irritation than a serious issue.
(but you could stick the tablet to your fridge if you wanted to)

 

[FoxhallGH]

The situation you describe doesn't affect the safe navigation of your drone, it just means the orientation of the radar display is wrong.
Home is still in the centre so you could still use it to fly home blind.
I used to fly with a tablet that was the best back in its day .. except the maker fitted 6 powerful magnets inside the case of the tablet.
It was impossible to calibrate the tablet's compass but that was more a minor irritation than a serious issue.
(but you could stick the tablet to your fridge if you wanted to)

True - I've found it very useful however, to use the map view to swing the drone round to fly back to me at the farthest point in a flight ... If the arrow wasn't pointing the way the drone was actually oriented, it wouldn't be a disaster (in most cases), but it would be a pain.
I flew a hover test a couple of weeks ago, and had a NetDot magnetic micro-USB plugged into the side of my RC controller to keep it charged while the flight wen't on through several batteries. I noticed that I got a gradual descent which I think was due to the magnetic block on the end of the NetDot cable - as all was OK when I changed to a standard micro-USB.
@Meta4 - Did you see any effects like that due to the mag's in the tablet you mentioned above??

 

[Meta4]

I flew a hover test a couple of weeks ago, and had a NetDot magnetic micro-USB plugged into the side of my RC controller to keep it charged while the flight wen't on through several batteries. I noticed that I got a gradual descent which I think was due to the magnetic block on the end of the NetDot cable - as all was OK when I changed to a standard micro-USB.
@Meta4 - Did you see any effects like that due to the mag's in the tablet you mentioned above??

No .. I wouldn't expect magnetic influences around the controller or tablet would have any effect on altitude holding.
The first suspect would be the barometer and the effect of temperature change on it.

 

[Kilrah]

On the MP remote the gimbals are magnetic, so a magnet placed just at the "right" location can cause the controller so sense a non-existent stick input. Should be easy enough to see though.

 

[Rocket Man]

The best way to ensure you fly safe, is to properly understand how your drone really works.
Believing and adhering to procedures that have proved to be incorrect is not "best practice".

Hey mate, Happy holidays...Fly safe .

 

[Rocket Man]

It's interesting that there have been reported incidents involving 'compass' issues in the forum, which have actually pointed to the compass in the mobile iOS / Android device needing calibration. A pre-flight factor to be wary of, is to check that the little red arrow-head denoting your Drone on the map in the bottom left corner of Go 4, is actually pointing in the same direction that the [physical] drone is ... You'd be surprised how many times it isn't - and how many times it's ignored. Rather than worrying too much about compass calibration on your drone, have a look at the compass calibration steps needed in your iOS / Android mobile - as that's probably just as important to your accurate navigation.

Interesting concept, will have to keep that in mind.

How to calibrate the compass on your Android phone | AndroidPIT