Incorrect altitude readout?

[ClearPropMedia]

Anyone else have an issue with their M3 altitude reading? Flown it a few times and not noticed this issue. Today, flying at the beach I took off and landed from the same spot and at one point, it was reading 0ft when I was 30 ft off the ground in the distance and when I landed it, it said -20ft. Restarted drone, took off again and it was fine and then mid flight, altitude changed again. Landed at about -10ft.

Does it need calibration? Or does this sound like a fault?

 

[globetrotterdrone]

Altitude Reading Issues

I'm getting a bad altitude readout when flying the M3. During the flight my altitude starts to go into the negative range. For instance I could be at 12 foot and it says -8 feet. There is a video of a Chinese tested flying the drone before it came out and it's showing the same issue. Negative...

mavicpilots.com

 

[BlairAir]

This has been observed by a number of Mavic 3 owners, including myself. One would hope it's a firmware calibration issue, and not a high failure on the part of DJI suppliers of electronic barometer components or SOC that has a hardware fault. It's of some comfort that many are experiencing it, since that supports a firmware issue as more likely source.

 

[ClearPropMedia]

This has been observed by a number of Mavic 3 owners, including myself. One would hope it's a firmware calibration issue, and not a high failure on the part of DJI suppliers of electronic barometer components or SOC that has a hardware fault. It's of some comfort that many are experiencing it, since that supports a firmware issue as more likely source.

Thanks for the clarification! Did you try IMU calibration and have the same problem?

 

[bkushner]

I'm on my second unit and same issue. I get up to -170 feet sometimes..check my message here. More on Altitude issues

 

[jonatious]

This has been observed by many people, this is a dangerous problem in terms of causing the pilot to fly over 400ft and get hefty fines

 

[ClearPropMedia]

I'm on my second unit and same issue. I get up to -170 feet sometimes..check my message here. More on Altitude issues

Sorry to hear you’re having the same issue! Hope they fix it in a future update.

 

[bkushner]

This has been observed by many people, this is a dangerous problem in terms of causing the pilot to fly over 400ft and get hefty fines

Tell me about it. Part of the area I fly has a height limit of 196 feet.

 

[BlairAir]

I did an IMU calibration, Compass Calibration and a gimbal calibration and RC calibration out if the box. I have done at least one IMU, Compass and gimbal since. I cannot say in what sequence, nor have I been tracking this altitude issue. I have had it occur, is as much as I can contribute.

I am somewhat more concerned about the climbing altitude without stick input issue. This occurs with APAS in Bypass mode. When it happens, the sun is low in the sky, and despite being 40 or more meters above obstacles, Mavic 3 gets yellow radar flashes showing obstacles under the Aircraft. If the Compass is displayed instead of maps, there are Yellow dots, blocks and groupings on the Compass. At some points the audible obstacle alerts start, and the aircraft keeps climbing all the way to max altitude with absolutely no left stick throttle application.

This has been observed by many people, this is a dangerous problem in terms of causing the pilot to fly over 400ft and get hefty fines

That can only happen if your max altitude is set over 400ft. I used to keep it right at 400, but observed it would go all the way to 400. To keep on the right side of the law, I use the default of 393. My replacement M3 hasn't done the climbing behavior yet, but I've only had it out a few times. It definitely is getting ghosting on the bottom sensors in low sun conditions especially when flown in large arcs or slowly circling. I have found "brake" vs Bypass seems to eliminate the altitude increasing.

 

[Meta4]

I did an IMU calibration, Compass Calibration and a gimbal calibration and RC calibration out if the box. I have done at least one IMU, Compass and gimbal since. I cannot say in what sequence, nor have I been tracking this altitude issue. I have had it occur, is as much as I can contribute.

Recalibrating the gimbal and compass won't have any effect on the height showing on your screen.
That comes entirely from your IMU.

I am somewhat more concerned about the climbing altitude without stick input issue. This occurs with APAS in Bypass mode. When it happens, the sun is low in the sky, and despite being 40 or more meters above obstacles

The obstacle it's trying to avoid is the sun.
If you have this issue and therfe are no obstacles around to avoid, turn obstacle avoidance off.
That should solve the issue.

 

[jonatious]

That can only happen if your max altitude is set over 400ft. I used to keep it right at 400, but observed it would go all the way to 400. To keep on the right side of the law, I use the default of 393

As others say if the altitude measurement is 100ft off, then 393 will barely make a difference

 

[BlairAir]

Recalibrating the gimbal and compass won't have any effect on the height showing on your screen.
That comes entirely from your IMU.

The obstacle it's trying to avoid is the sun.
If you have this issue and therfe are no obstacles around to avoid, turn obstacle avoidance off.
That should solve the issue.

Well aware of it. Did you not see my reference to low sun? Turning obstacle avoidance off is entirely self defeating. I do not have the OPs problem with altitude being off 100 feet or more. I did get a negative (-6 feet) on several flights.
Also quite aware that a gimbal calibration is completely unrelated to these issues. The point was that I calibrated all available systems in the Aircraft, as any thorough troubleshooting session would demand. I'm an IT pro with decades of experience with new hardware, firmware fixes and failures, bug decoding and systems analysis... not some guy who went on Amazon to buy a new toy.

 

[BlairAir]

As others say if the altitude measurement is 100ft off, then 393 will barely make a difference

The OP has a serous hardware failure. Period. I was referring specifically to uncommanded altitude increases, a point raised separately. The OP did not specify he had this issue. I doubt the FAA, if presented with flight log data would impose fines on a drone flying above restrictions... once. If the pilot continues to fly with a drone flying above legal altitudes, that's I'm them. My issue was the M3 flying up TO max altitude. It never, under any conditions went above it. The mis-reported altitudes I observed on my first Mavic 3 (I'm on #3) were about 6 feet off.
Thus the 393 - allowing for 6 feet + 1
The OP should be offered an exchange. DJI is processing many many returns and exchanges, but they need to do another. It's his right to demand an exchange or return. The issues that he is experiencing are unacceptable.

 

[ClearPropMedia]

The OP has a serous hardware failure. Period. I was referring specifically to uncommanded altitude increases, a point raised separately. The OP did not specify he had this issue. I doubt the FAA, if presented with flight log data would impose fines on a drone flying above restrictions... once. If the pilot continues to fly with a drone flying above legal altitudes, that's I'm them. My issue was the M3 flying up TO max altitude. It never, under any conditions went above it. The mis-reported altitudes I observed on my first Mavic 3 (I'm on #3) were about 6 feet off.
Thus the 393 - allowing for 6 feet + 1
The OP should be offered an exchange. DJI is processing many many returns and exchanges, but they need to do another. It's his right to demand an exchange or return. The issues that he is experiencing are unacceptable.

Is this a hardware failure though? This seems to be a major problem for a lot of people. I am thinking it is more likely a software problem given the extent of the issue?

My drone has also climbed with the sun low in the sky. It did this a couple of days ago at Sunset

 

[BlairAir]

I'm referring to the OP having altitude of -170 feet etc. It is not directly related to the climbing altitude issue. I haven't seen any other report of such massive altitude height misreporting. Do you have onscreen altitude numbers reporting hundreds of feet off? DJI has acknowledged and is indeed working on the sensors causing altitude changes. Also on altitude numbers mismatched by a few percent, but the OPs numbers are not slightly off. He seems to have something way out of wack.

 

[ianwood]

A barometer is a simple device. It either works or doesn't. If I had to guess, there are gremlins in APAS 5 that are yet to be worked out. It would seem low light and operating over water may be some of the conditions in which this can occur.

 

[ClearPropMedia]

Anyone else still having this issue?

Took off and landed from the same point in the park today. Each flight lasted maybe 15 minutes. Upon landing, I was at -15ft and the second time -6ft. My Mini 2 doesn’t do this. Conditions were clear, a little bit of wind at around 4:30 PM. Was hoping the new firmware would fix it but nope!

One time out over the ocean I was at 40ft and it was reading 0ft and then when landing about -30ft. This was one time so far though!

 

[Meta4]

Anyone else still having this issue?

Took off and landed from the same point in the park today. Each flight lasted maybe 15 minutes. Upon landing, I was at -15ft and the second time -6ft. My Mini 2 doesn’t do this. Conditions were clear, a little bit of wind at around 4:30 PM. Was hoping the new firmware would fix it but nope!

One time out over the ocean I was at 40ft and it was reading 0ft and then when landing about -30ft. This was one time so far though!

Everyone does.
It's common and completely normal to have small changes in indicated altitude during the duration of a flight.
That's the nature of things when measuring height with a barometric sensor.

 

[Klovix]

Same here, with incorrect altitude readings in my Air 2S.
I’ve been flying it for a month now. Everything was ok until last week.
I fly in a very flat area, and I was surprised to read that my drone was showing me altitudes of -17m when it was 2-3 meters high in front of me (take off point).
The only thing that has changed lately is my style of flying, trying to practise spirals while changing altitude,
sharp turns, and I was also changing modes in flight: Normal, then Sport, then Normal again.

This morning I flew it again, after calibrating compass and IMU, and look at this:


I understand that perhaps this is a common problem with some Mavic models, and the sensor for barometric altitude, but it’s very scary in certain situations.
Not sure if the Phantom or higher series have this same problem. Perhaps DJI want us to buy a better drone with better sensors if we need the altitude readings to be more acurate.

 

[Klovix]

Here's the log: