Magnetic Field Interference

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Today I was over a corn field in an area with no hills or obstructions for 2 miles in every direction and not near any buildings. I got three warnings in one minute for weak GPS and then a Magnetic Field Interference warning and my Phantom started flying in a very unstable way. Thankfully I was able to get it down without a crash but had I been next to buildings or people I’m afraid of what might have happened. My drone is an Obsidian Phantom 4 Pro +. I’m not sure if it needs to be sent in for repairs or what to do. I’m definitely reluctant to put it back into the air. I have never had any gps problems here and I had been flying for about 20 minutes before the incident occurred. Hopefully you guys can help me out. Thank you
 

ianzone

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Um done compass calibration, might pay to do imu calibration aswell
 

Meta4

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Today I was over a corn field in an area with no hills or obstructions for 2 miles in every direction and not near any buildings. I got three warnings in one minute for weak GPS and then a Magnetic Field Interference warning and my Phantom started flying in a very unstable way. Thankfully I was able to get it down without a crash but had I been next to buildings or people I’m afraid of what might have happened. My drone is an Obsidian Phantom 4 Pro +. I’m not sure if it needs to be sent in for repairs or what to do. I’m definitely reluctant to put it back into the air. I have never had any gps problems here and I had been flying for about 20 minutes before the incident occurred. Hopefully you guys can help me out. Thank you
If you are up in the air at normal flying heights, you aren't going to get any magnetic influences from down on the ground.
The source of the issue is something else.
Your flight data might help understand what might have happened and also a description of your launch spot would be helpful.
What was the surface you launched from?
 
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If you are up in the air at normal flying heights, you aren't going to get any magnetic influences from down on the ground.
The source of the issue is something else.
Your flight data might help understand what might have happened and also a description of your launch spot would be helpful.
What was the surface you launched from?
I launched from my deck behind my house. It’s made of fake wood composite materials with a wooden frame.
 

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Today I was over a corn field in an area with no hills or obstructions for 2 miles in every direction and not near any buildings. I got three warnings in one minute for weak GPS and then a Magnetic Field Interference warning and my Phantom started flying in a very unstable way. Thankfully I was able to get it down without a crash but had I been next to buildings or people I’m afraid of what might have happened. My drone is an Obsidian Phantom 4 Pro +. I’m not sure if it needs to be sent in for repairs or what to do. I’m definitely reluctant to put it back into the air. I have never had any gps problems here and I had been flying for about 20 minutes before the incident occurred. Hopefully you guys can help me out. Thank you
Good chance , that your deck was the initial cause of the Compass being affected.
It does not take much , you may have put it on or under a nail .

Magnetic interference is tricky on the Phantoms not as much on the Mavics but the Phantoms seem more fragile.

I made this video to show how Susceptible the Phantom is to magnetic Interference and how fast the warning goes away.
Most likely your drone is fine, and you just need to watch your take off area and the warning flashing quickly on the scree.

Phantomrain.org
Gear to fly your Phantom in the Rain and Float on Water.

 

Meta4

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I launched from my deck behind my house. It’s made of fake wood composite materials with a wooden frame.
With screws/nails or bolts that could have been within a few inches of the drone?
Your flight data would help to see what happened.

Go to DJI Flight Log Viewer | Phantom Help
Follow the instructions there to upload your flight record from your phone or tablet.
That will give you a detailed report on the flight data.
Come back and post a link to the report it gives you.
 
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With screws/nails or bolts that could have been within a few inches of the drone?
Your flight data would help to see what happened.

Go to DJI Flight Log Viewer | Phantom Help
Follow the instructions there to upload your flight record from your phone or tablet.
That will give you a detailed report on the flight data.
Come back and post a link to the report it gives you.
Ok I will do that tonight after work and put it up. I didn’t know it could be that small of an interference. It does have metal screws. Those can mess up my drone even that much later into the flight? I did some point of interest videos and an active track before the incident happened and everything went fine.
 
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Today I was over a corn field in an area with no hills or obstructions for 2 miles in every direction and not near any buildings. I got three warnings in one minute for weak GPS and then a Magnetic Field Interference warning and my Phantom started flying in a very unstable way. Thankfully I was able to get it down without a crash but had I been next to buildings or people I’m afraid of what might have happened. My drone is an Obsidian Phantom 4 Pro +. I’m not sure if it needs to be sent in for repairs or what to do. I’m definitely reluctant to put it back into the air. I have never had any gps problems here and I had been flying for about 20 minutes before the incident occurred. Hopefully you guys can help me out. Thank you
UK seems to be undertaking certain anti drone activities. The CAA is advising on areas were interference is being tested. - See the CAA website
 

ianzone

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Good chance , that your deck was the initial cause of the Compass being affected.
It does not take much , you may have put it on or under a nail .

Magnetic interference is tricky on the Phantoms not as much on the Mavics but the Phantoms seem more fragile.

I made this video to show how Susceptible the Phantom is to magnetic Interference and how fast the warning goes away.
Most likely your drone is fine, and you just need to watch your take off area and the warning flashing quickly on the scree.

Phantomrain.org
Gear to fly your Phantom in the Rain and Float on Water.

Wow great vid showing what happens,,some good info there,learn something everyday,, yes I can say if it came up and disappeared I would just fly without 2nd thought of that,,now something else to remember lol,,thanks for sharing
 
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Meta4

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I got three warnings in one minute for weak GPS and then a Magnetic Field Interference warning and my Phantom started flying in a very unstable way.
The issue was a yaw error situation.
It was unusual that it happened after so much flying around rather than the first time you turned the drone significantly after launching.
It must have been a small one, with very little difference between actual north and the false north that the gyro sensors were initialised with.
You were very lucky, usually a yaw error results in an uncontrollable drone making a high speed crash.

These are caused by powering on close to steel objects.
Small items like screws etc would have to be quite close to the compass to cause this.
You can still launch from the deck and avoid them in future if you just have a box or something like that to keep the drone a foot of so above the deck.
 
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ianzone

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Gosh have I been lucky too,I think this is good lesson for us all,,,as post #5 says ""error is disguise alright ""amount of times I must have flown with a error and not realize or been affected probably like most of us until it bites has now made me aware of where I now launch from,I never gave a care before cause app tell me ok even though a error has occurred in the background,,
👍this probably explains half the crashs going on around the place
 

Meta4

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I never gave a care before cause app tell me
It's not the situations where the compass detects a strong influence and identifies it as a problem that you need to worry about.
It's when the magnetic effect isn't strong enough for the compass to identify the problem, but still enough to deflect the compass.
More details here.
 
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The issue was a yaw error situation.
It was unusual that it happened after so much flying around rather than the first time you turned the drone significantly after launching.
It must have been a small one, with very little difference between actual north and the false north that the gyro sensors were initialised with.
You were very lucky, usually a yaw error results in an uncontrollable drone making a high speed crash.

These are caused by powering on close to steel objects.
Small items like screws etc would have to be quite close to the compass to cause this.
You can still launch from the deck and avoid them in future if you just have a box or something like that to keep the drone a foot of so above the deck.
Would you suggest I send it in for repairs or from what you’ve seen is it more of an error on my end?
 

Meta4

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Would you suggest I send it in for repairs or from what you’ve seen is it more of an error on my end?
It's nothing that needs repairing.
Every time you power on the drone, the gyro is initialised from the compass.
If the compass is deflected by being close to steel, the gyro is initialised with a false reading.
If that results in a bad crash, the drone needs repairing.
If it was a small yaw error and the drone was recovered safely, it gets powered down and the gyro is reinitialised next time the drone is powered on.

Just avoid launching from reinforced concrete or anywhere with screws/bolts/nails etc close to the drone.
 
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It's nothing that needs repairing.
Every time you power on the drone, the gyro is initialised from the compass.
If the compass is deflected by being close to steel, the gyro is initialised with a false reading.
If that results in a bad crash, the drone needs repairing.
If it was a small yaw error and the drone was recovered safely, it gets powered down and the gyro is reinitialised next time the drone is powered on.

Just avoid launching from reinforced concrete or anywhere with screws/bolts/nails etc close to the drone.
cant thank you enough for the help. I’ve got my Private Rotorcraft license and I’m almost to commercial but this drone stuff is new to me so it’s very humbling lol
 
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cant thank you enough for the help. I’ve got my Private Rotorcraft license and I’m almost to commercial but this drone stuff is new to me so it’s very humbling lol
Ok, just took it out to test fly it and every time I pick up off the ground in loses GPS before it even gets the 4 ft off the ground from auto takeoff. Any ideas?
 

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Ok, just took it out to test fly it and every time I pick up off the ground in loses GPS before it even gets the 4 ft off the ground from auto takeoff. Any ideas?
Has it had a crash to could cause a loose connection?
Does it do this in another location?
 
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I tried several places in the yard and did a bunch of calibrations. im probably going to send it in for repair.
 

ianzone

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It's not the situations where the compass detects a strong influence and identifies it as a problem that you need to worry about.
It's when the magnetic effect isn't strong enough for the compass to identify the problem, but still enough to deflect the compass.
More details here.
Thanks yip learn something everday...hey sure I said that yesterday too 😇and the day before
 

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