Weird behavior at night in one specific place (MA2). Can someone understand what's happening?

[Yaros]

Hey! I have been flying the Mavic Air 2 for 3 months, and it's great.
My favorite takeoff place is the top floor of my apartment building, it's easy to go there, and I always have good signal with good range.
But there is a strange occurrence that I noticed when flying at night or late evening (after 7 PM)! The drone always requires compass calibration if I try to fly at 7 PM or later, which seems odd, especially taking in account that when trying to takeoff from other locations it doesn't require any calibration. After that compass calibration it works just fine, but there is a reason it does ask for it, and maybe it's not a good one! Also, sometimes when I takeoff at evening or night after the takeoff the gimbal goes sideways, like it's not calibrated! I manually correct it from settings while it's hovering, but why can this happen?? I fly there almost every day and during day hours everything is like usual, but when it's evening or night it always happens! Could someone of you explain, what can it really be?

First, I blamed it on the Satellite Antennas (5 antennae) that maybe when people start watching TV it messes with the magnetic field, but after reading a little online I read that satellite antennas which are receivers normally can't interfere with signals. Is that true?
If it is, then what else could it be that only at night and only at that place would make my drone mess up its compass and gimbal calibration?
Any ideas?

 

[Starz]

Reading material.

Night flight compass calibration

My Mini 2 compass won't calibrate after dark. Is this normal? I see videos of people flying at night....but mine fails every time. It's only a few weeks old but had never been able to calibrate at night. Works fine in the daylight, but needs compass calibration every time I turn it on after...

mavicpilots.com

 

[eEridani]

Does the calibration issue happen at night if you DON'T attach the strobe?

I found my U-DR-02 changes the compass calibration on my Air 2 - so it is now back in the box.

ps: it isn't the sat TV dishes. The RF coming in from the sats is the same regardless of who's watching. And is much too small a signal to affect the drone. If you have a telecom repeater on your roof (a couple of sideways pointing dishes), that's a different story, they can dump out enough power to overwhelm a drone - and probably not a good place to be standing for extended periods.

 

[Yaros]

Does the calibration issue happen at night if you DON'T attach the strobe?

I found my U-DR-02 changes the compass calibration on my Air 2 - so it is now back in the box.

ps: it isn't the sat TV dishes. The RF coming in from the sats is the same regardless of who's watching. And is much too small a signal to affect the drone. If you have a telecom repeater on your roof (a couple of sideways pointing dishes), that's a different story, they can dump out enough power to overwhelm a drone - and probably not a good place to be standing for extended periods.

It does, even without the strobe attached. And I don't have anything else than the satellite antennas.
When I go there next time I will take a photo and attach it here!

 

[tlswift58]

Does the calibration issue happen at night if you DON'T attach the strobe?

I found my U-DR-02 changes the compass calibration on my Air 2 - so it is now back in the box.

ps: it isn't the sat TV dishes. The RF coming in from the sats is the same regardless of who's watching. And is much too small a signal to affect the drone. If you have a telecom repeater on your roof (a couple of sideways pointing dishes), that's a different story, they can dump out enough power to overwhelm a drone - and probably not a good place to be standing for extended periods.

I missed where he had a strobe attached, so reread the post like 3 times. Not sure how you knew they used a strobe, but cool.

Guess one main question would be - do you stand / fly at same spot during day and night? If not, then where you may stand / fly from may have more magnetic interference in that area versus a different part. With limited info, hard to say what may be cause.

 

[cgmaxed]

I missed where he had a strobe attached, so reread the post like 3 times. Not sure how you knew they used a strobe, but cool.

Guess one main question would be - do you stand / fly at same spot during day and night? If not, then where you may stand / fly from may have more magnetic interference in that area versus a different part. With limited info, hard to say what may be cause.

I think most hobbyists use strobes at night regardless if it's required or not. I stopped using them, due to the attention it brought to my drone by people on the ground and even police. People just get so paranoid when they see drones or a drones lights flying over them or just passing by. For the drones that I can't turn the running LEDs off, I painted them black. I never memorized what the blinking patterns meant anyway. When flying or landing I just turn the landing lights on and off when needed.

 

[wardtom084]

The police wanted to see my drone. One of them had already flown it. I think you should show it off to everyone and let them fly it. Only way you are going to break the bad news that we get from time to time.

 

[Yaros]

I missed where he had a strobe attached, so reread the post like 3 times. Not sure how you knew they used a strobe, but cool.

Guess one main question would be - do you stand / fly at same spot during day and night? If not, then where you may stand / fly from may have more magnetic interference in that area versus a different part. With limited info, hard to say what may be cause.

I do stand and take off in the same exact spot (1 meter more or less) and yet don't have the problem during the day. Today I have flown again and needed to calibrate the compass at night again, just ridiculous.

 

[Dave Maine]

Hand launch or from rooftop? Does the compas heading agree with the tablet display when you power up on the launch point?

 

[cgmaxed]

I do stand and take off in the same exact spot (1 meter more or less) and yet don't have the problem during the day. Today I have flown again and needed to calibrate the compass at night again, just ridiculous.

That's really strange. Maybe a neighbor or some electronics in the area turn on after dark or around the specified time you experience this issue, thus affecting the function of the drone.

 

[Yaros]

It is worrying me, and there is a reason!
Today I was flying again from there more or less at 18:30 - 19:30 and the gimbal was tilting a lot! There wasn't any wind, but the gimbal was tilting to 20 degrees or more! I know other people that have experienced similar issues, and almost always it was because they were flying near a telecom or TV transmitter, which is not really good. The gimbal seems to go haywire every 3 - 5 minutes and I correct it with the Manual Gimbal Calibration, then in 3 minutes or so it reverses, returns to normal and I correct it back to 0 offset. in 4 - 5 minutes the situation repeats. Again, ONLY during evening or night this happens, EXTREMELY weird, isn't it?!
I thought: Maybe WiFi interference? Nah, I can fly up to 3km on 100 meters height so definitely not, because when I was on a location with a lot of WiFi interference I could only go to 900 meters in 100 meters height...
I really need to try to fly in a completely different location and see if it happens maybe.

What else could it be? Any suggestions? Is this an issue with my drone?

 

[Robert Prior]

I really need to try to fly in a completely different location and see if it happens maybe.

That's the next thing to try. Can you find a location away from all possible interference, like an open park not near any transmitters?

At your building, if there is anything like a cell phone repeater installed that might be a factor, as people come home and start to use their phones at home. (Shouldn't interfere, but you might be getting some strange resonances off metal in the building — I dimly remember something about that in the one class on RF design I took nearly four decades ago. Could well be wrong about that. Another possibility might be high-current wires nearby generating magnetic fields, and not running during the day.)

But first try from another location away from electronics. That should narrow it down to your drone or some kind of interference.

 

[VenomXts]

I also have this issue when it gets dark coming in and landing then it is required to take back off with my air2. I honestly think its a failsafe because the camera doesn't get enough information and the fact im landing on concrete with rebar.

Be interested in hearing the real reason though.

 

[Yaros]

That's the next thing to try. Can you find a location away from all possible interference, like an open park not near any transmitters?

At your building, if there is anything like a cell phone repeater installed that might be a factor, as people come home and start to use their phones at home. (Shouldn't interfere, but you might be getting some strange resonances off metal in the building — I dimly remember something about that in the one class on RF design I took nearly four decades ago. Could well be wrong about that. Another possibility might be high-current wires nearby generating magnetic fields, and not running during the day.)

But first try from another location away from electronics. That should narrow it down to your drone or some kind of interference.

I flew yesterday in another location, the house of my friend and the problem didn't happen, so it is something in that specific location, but now is the question: What is it?

 

[Yaros]

I also have this issue when it gets dark coming in and landing then it is required to take back off with my air2. I honestly think its a failsafe because the camera doesn't get enough information and the fact im landing on concrete with rebar.

Be interested in hearing the real reason though.

Yes it might be, but now I'm talking about the gimbal tilting, do you also have this issue?

 

[VenomXts]

Yes it might be, but now I'm talking about the gimbal tilting, do you also have this issue?

I am not sure what you mean, your gimble isn't level? My issues is it forces me to calibrate and sometimes even after wont let me take off still.

 

[Yaros]

I am not sure what you mean, your gimble isn't level? My issues is it forces me to calibrate and sometimes even after wont let me take off still.

Yes I also have that, but then the gimbal starts to go a little crazy on the horizontal axis... And yes, I tried to calibrate the gimbal multiple times, it's definitely some kind of interference.

 

[Yaros]

Today I flew during the day and had no issues whatsoever with the gimbal!
Pretty strange, I guess!

 

[Robert Prior]

I flew yesterday in another location, the house of my friend and the problem didn't happen, so it is something in that specific location, but now is the question: What is it?

Do you have something that will measure magnetic field strength?

My guess would be there's some equipment close to where you take off from that has high current only at night, so it is generating strong magnetic field only at night. Transformer, power line, motor… lots of possible causes.

You could also try at different times, like 10 PM, 12 PM, 2 AM, which might provide clues as to what is causing it. Eg. is it during hours of darkness? When people are home for evening and likely cooking/cleaning? Every day or only specific days?

Simplest approach would be to measure magnetic field strength, though. I have a small sensor that will do that (Pocketlab Voyager). Some cell phones also have a field sensor that you can access (download Physphox and see if your phone has a magnetomoeter).

Your smartphone is a mobile lab.

Download for free: Follow us: Features Sensors Phyphox allows you to use the sensors in your phone for your experiments. For example, detect the frequency of a pendulum using the accelerometer or measure the Doppler effect using its microphone. Data Export Export your data i

phyphox.org

 

[cgmaxed]

Do you have something that will measure magnetic field strength?

My guess would be there's some equipment close to where you take off from that has high current only at night, so it is generating strong magnetic field only at night. Transformer, power line, motor… lots of possible causes.

You could also try at different times, like 10 PM, 12 PM, 2 AM, which might provide clues as to what is causing it. Eg. is it during hours of darkness? When people are home for evening and likely cooking/cleaning? Every day or only specific days?

Simplest approach would be to measure magnetic field strength, though. I have a small sensor that will do that (Pocketlab Voyager). Some cell phones also have a field sensor that you can access (download Physphox and see if your phone has a magnetomoeter).

Your smartphone is a mobile lab.

Download for free: Follow us: Features Sensors Phyphox allows you to use the sensors in your phone for your experiments. For example, detect the frequency of a pendulum using the accelerometer or measure the Doppler effect using its microphone. Data Export Export your data i

phyphox.org

Yeah, it sounds like some type of equipment that produces radio interference is being turned on at night or as said, when people are returning home from work. It could be someone with a high powered internet connection that gets turned on at night for all we know. Someone may just be using some equipment at night that produces significant radio interference.