Extreme Interference grounded a Mission ????

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Not sure just where to post this so I'll try the old Phantom Gang. I arrived at a site to shoot a Litchi mission today as the weather, wind and iight finally smiled. I'm still guessing as to just what happened but there was a concrete picnic table that was chosen for mission start and home point. Upon power ups, both Litchi and DJ Go started chirping about extreme electromagnetic inteference. Please caibrate the Phantom.

Calibration failed about 10 times as I moved in a 10 foot circle from this picnic table, all with calibration failures from various points. Was it my Tundra parked 12 feet away? No, I succeded in calibrating from the tail gate. I crossed the road about 25 feet from this table and also succeeded.. Kept going back and failing in the 10 ft. ring with table centered. Below, I've included a pretty exact long, lat for this table here in Jefferson Maine.

I could have gone ahead and try to fly the mission, but table was very near the first and last waypoints and I was wondering what penalty might await if I flew or hovered through this wormhole.

Load up this coord in sattellite view and see if you agree that this spot was artificially raised and flattened and may have metal supports inground, causing the interference? The spot is a placarded (is that a word?) memorial spot meant for quiet contemplation with a million dollar view of Damariscotta lake and some of its islands, all the subjects of this project._ Due east from the table falls away rapidly. I suspect I could have moved east and launched but the snow was deep and burrdock (cockleburrs we used to call em) even deeper.

No issues (that is no interfernec messages and no calibration issues) across the road at the Church.

My experience is that a calibration is a rare require and I also think that doing it every time you fliy you are asking for trouble. If you travel a hundred or 2 miles away, then I'd consider it.

GO here:

44.130728, -69.514269
 

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...there was a concrete picnic table that was chosen for mission start and home point. Upon power ups, both Litchi and DJ Go started chirping about extreme electromagnetic inteference. Please calibrate the Phantom.
My first thought is that any concrete picnic table would probably have some sort of internal rebar. I don't know if that's a fact or not, but I do know that if it were me I would have been perhaps overly cautious and launched from somewhere else. I for sure would not have recalibrated and especially not from the tailgate of a vehicle. I suggest that you find a large field somewhere, go to the center of it and then recalibrate so you have a known good calibration. Then leave it alone. :)
 

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Not sure just where to post this so I'll try the old Phantom Gang. I arrived at a site to shoot a Litchi mission today as the weather, wind and iight finally smiled. I'm still guessing as to just what happened but there was a concrete picnic table that was chosen for mission start and home point. Upon power ups, both Litchi and DJ Go started chirping about extreme electromagnetic inteference. Please caibrate the Phantom.

Calibration failed about 10 times as I moved in a 10 foot circle from this picnic table, all with calibration failures from various points. Was it my Tundra parked 12 feet away? No, I succeded in calibrating from the tail gate. I crossed the road about 25 feet from this table and also succeeded.. Kept going back and failing in the 10 ft. ring with table centered. Below, I've included a pretty exact long, lat for this table here in Jefferson Maine.

I could have gone ahead and try to fly the mission, but table was very near the first and last waypoints and I was wondering what penalty might await if I flew or hovered through this wormhole.

Load up this coord in sattellite view and see if you agree that this spot was artificially raised and flattened and may have metal supports inground, causing the interference? The spot is a placarded (is that a word?) memorial spot meant for quiet contemplation with a million dollar view of Damariscotta lake and some of its islands, all the subjects of this project._ Due east from the table falls away rapidly. I suspect I could have moved east and launched but the snow was deep and burrdock (cockleburrs we used to call em) even deeper.

No issues (that is no interfernec messages and no calibration issues) across the road at the Church.

My experience is that a calibration is a rare require and I also think that doing it every time you fliy you are asking for trouble. If you travel a hundred or 2 miles away, then I'd consider it.

GO here:

44.130728, -69.514269

Looking on the map this does look like a good spot , and I have flown off many a picnic table without magnetic interference so before you rule out the Truck I would test it out a few different ways.

Screenshot 02-23-2020 00.06.20.png


See if you can take off the hood of the truck and fly the drone from inside the Tundra this might give you a better idea as to what is really causing the issue.

You can also isolate the Picnic Table also , but as far as the penalty for pushing thu magnetic interference it can lead to a fly away in atti mode and that can lead to Yaw Errors which means even bigger problems so you made the right decision.

But I would find out if your truck is really drone friendly both front and back so you can lay that to rest.

Phantomrain.org
Gear to fly your Phantom in the rain.
Coal
 
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Thanks folks. I've flown many times with the Tundra nearby when testing things all with no issues. I don't make a habit of flying from the truck and have never flown from inside the cab. I'll have to reconfigure this mission using new waypoints.

Moral of the story, a phantom or large drone would plow through and out of that field of interference at speed no worse for the ware in most cases, but is sure seems to be a random trap awaiting the RPIC. Suppose I was merely flying nearby and decided to land on said table. That might prove to be interesting (or not).

A google street view to this spot explains why I'm a bit miffed about the mission abort.

Screen Shot 2020-02-23 at 10.26.06 AM.png


I'll naturally post my video alternative when complete. Truth be told, this is a challenging time of the year with old brown spotty snow lying around for desirable videos - get your editing chops up to speed!

Thanks again Phantomdom.
 
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Toyota truck? Mine is magnetic or something, cannot takeoff within 10ft of it. Compass calibration needed every time. Move away and all is fine. My drones literally drift towards it when close. Would never calibrate near it or asking for trouble. Good luck.

something has changed because I used to be able to takeoff from the bed of the truck with no problems.
 
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Toyota truck? Mine is magnetic or something, cannot takeoff within 10ft of it. Compass calibration needed every time. Move away and all is fine. My drones literally drift towards it when close. Would never calibrate near it or asking for trouble. Good luck.
Yup'...08 Long Bed and I do NOT have your issue. I also do not calibrate often and usually am never asked to. Whatever was going at this location was enough to keep the bird from calibrating at all and this was a first for me on the interference front.

The tailgate is my setup surface, but I don't takeoff and land from it to be sure. I think I might invest in a smallish foldable portable table finally as a place to setup in the field. This is not always feasible or desirable I know, but it will help me stay organized. It takes me 20 minutes to setup my Inspire with checklists before sticks go down and out. I can imagine an M210 taking even longer.
 
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Yup'...08 Long Bed and I do NOT have your issue. I also do not calibrate often and usually am never asked to. Whatever was going at this location was enough to keep the bird from calibrating at all and this was a first for me on the interference front.

The tailgate is my setup surface, but I don't takeoff and land from it to be sure. I think I might invest in a smallish foldable portable table finally as a place to setup in the field. This is not always feasible or desirable I know, but it will help me stay organized. It takes me 20 minutes to setup my Inspire with checklists before sticks go down and out. I can imagine an M210 taking even longer.

So that picnic table is no ordinary picnic table, it looks like it might have been made from grave stones.
Yikes, that was mostl likely the issue , ;)
 
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My ‘06 is terrible to fly around. But, It’s my only transport.

I have rarely recalibrated the compass on any of my Phantoms (and Mavic). I can, almost, always move away from the interference and find clean air. Even after traveling 600 miles, no difference. Worst case, I hold it over my head and hand launch, in clean air. Remove all other electronics from area if necessary. Only after all that, will I recalibrate.😃👍😎Enjoy

I have a fold out aluminum table that I use, but it’s too small for Phantoms. Going to upsize, but works.
 
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um, what? this is opposite of normal advise!

Placing the drone just on top of the hood of the car or truck will let you know if your getting magnetic interference also the truck bed as mentioned by others.

So if you have strong magnetic interference from the hood you most likely will not want to be taking off anywhere in front of it.
 
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Placing the drone just on top of the hood of the car or truck will let you know if your getting magnetic interference also the truck bed as mentioned by others.

So if you have strong magnetic interference from the hood you most likely will not want to be taking off anywhere in front of it.
Correct, the front of my Tundra is where the magnetic interference originates. Far worse than the tailgate area. I have to stay 6 to 10 feet away from the hood or I will get the 'calibrate compass' warning.
 
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See if you can take off the hood of the truck
um, what? this is opposite of normal advise!
Placing the drone just on top of the hood of the car or truck will let you know if your getting magnetic interference
still makes no sense at all. to me this is very bad advise. for sure their will be interence from the top of a hood and their have been tons of warnings on the forum about never doing that.

@Oso @Fly Dawg @RodPad @Meta4 @BigAl07 - what are your feedbacks wrt taking off from the top of a car or truck? bad advise or not?
 

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still makes no sense at all. to me this is very bad advise. for sure their will be interence from the top of a hood and their have been tons of warnings on the forum about never doing that.

@Oso @Fly Dawg @RodPad @Meta4 @BigAl07 - what are your feedbacks wrt taking off from the top of a car or truck? bad advise or not?


Some of us actually do this quite often. I can launch from one point of the roof of my vehicle but another one gives me errors and I launch just fine.

IIRC @dirkclod launches from the top of his vehicle very often and he flies a LOT!!
 

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@Oso - what are your feedbacks wrt taking off from the top of a car or truck? bad advise or not?
I would never do it, nor would I ever recommend that anyone do it. It seems counterintuitive to me.

That being said, not everyone does things the same way so if something works for someone else then who am I to say differently. 😊
 

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That being said, not everyone does things the same way so if something works for someone else then who am I to say differently. 😊
That's VERY True!! There are many UAS things that I do that we don't teach/suggest but they work. Sometimes you just have to experiment and find out what works best for You and the way YOU work. We teach our students the safest and Best Practice but when we are out working for ourselves we do what works best for us.
 
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dirkclod

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Some of us actually do this quite often. I can launch from one point of the roof of my vehicle but another one gives me errors and I launch just fine.

IIRC @dirkclod launches from the top of his vehicle very often and he flies a LOT!!
Nooooo, the bed of my old truck. Would i lie to you ?
Now I drive a 2012 Ford and it won't let me but i fly from inside of it in the cab with the heat on . :)
 

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Nooooo, the bed of my old truck. Would i lie to you ?
Now I drive a 2012 Ford and it won't let me but i fly from inside of it in the cab with the heat on . :)


That's right... I was close... sort of LOL.
 
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Compass calibration is probably the most misunderstood aspect of drone flying.
Many flyers still don't understand what it does and when it is necessary.
DJI's documentation and warning messages contribute to the confusion.

The most important thing about compass calibration is to understand what it does (and doesn't) do.
The only thing compass calibration does is to identify and measure the magnetic fields that are part of your drone so they can be subtracted from compass data to provide accurate measurement of the local magnetic environment.
That's it, just one thing.

It has nothing to do with magnetic variation or declination, where you are in the world, how far you have traveled or nearby sources of magnetic interference.
Once done, the compass shouldn't lose calibration.
Recalibrating a perfectly good compass won't make anything "better" or safer.
The only time you need to calibrate the compass is when you modify the drone by adding or removing components or accessories or when you rebuild it.

I have been flying my P4 pro for 3.5 years.
I've traveled north-south 3000 miles and east-west over 4000 miles and never recalibrated anything on it.
It flies as well now as it did on day one.

I arrived at a site to shoot a Litchi mission today as the weather, wind and iight finally smiled. I'm still guessing as to just what happened but there was a concrete picnic table that was chosen for mission start and home point. Upon power ups, both Litchi and DJ Go started chirping about extreme electromagnetic inteference. Please calibrate the Phantom.
... My experience is that a calibration is a rare require and I also think that doing it every time you fliy you are asking for trouble. If you travel a hundred or 2 miles away, then I'd consider it.
Are you sure that's what the warning said?
DJI's warning message usually says Move aircraft or calibrate compass.
This is what mine does when placed on a car roof.
i-5CPNRw6-M.png

But the message is too big and scrolls across.
Because of the focus on compass calibration in forums, many people don't even notice the first part of the message.
If the compass is warning you that it's detected a magnetic field much stronger than normal (that's the magnetic interference part of the message), then recalibrating the compass won't do anything to fix the problem the compass is warning you about.
The only thing that will is to move away from the magnetic source that the compass is warning about.

The picnic table you showed is definitely full of steel.
There may be other buried steel nearby.
The compass was warning you that it was within a magnetic field that was stronger than normal.
It could have been a very large steel object 6-10 feet away.
It could have been something as small as a small steel bolt if it was just an inch or two from the compass.
Whatever it was, the compass was telling you to go somewhere else away from the problem.
DJI's poor wording makes people believe that recalibrating the compass might "fix" things but there's no way it could.
 
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I flew today over 700 miles from home and everything is working perfectly. Everything is in the low green range on the sensors. No calibrating of any kind.
 

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