Found the cause for my MP GPS failure...

[conchman]

Could power lines mess with the 2 compasses on board the drone?

 

[sar104]

Could power lines mess with the 2 compasses on board the drone?

No - at least not the power lines themselves unless the aircraft were very close - maybe within a couple of feet. The support towers could be ferromagnetic.

 

[Drgnfli]

I sent this link to DJI Arizona after reading all you folks comments. Here is what they said:

Thanks for the heads up. I'll forward this to our technicians.
A few quick things to bring up just for your comfort/knowledge:
A user explained how a cell phone or other equipments GPS isnt affected by powerlines and that can be because of a few different reasons. The biggest one is that most devices are using cell phone towers and triangulation in order to find its position, not multiple satellites. Beyond that, without going into incredible detail, not all electronics have similar components, and thus very different uses, resistances, and weaknesses.
I appreciate you giving us a heads up!

So, Droners, what do you think?
Personally, I will avoid high voltage power lines from now on.
Oh, BTW, I bought Travelers insurance many months ago for my Mavic Pro & they paid the full cost of the $217 repair costs. I had a $50 deductible but they did not apply it to this repair bill - go figure! In case you are interested that is Travelers Indemnity Co. of America.
Appreciate all the comments & suggestions - this is a great website...

 

[sar104]

I sent this link to DJI Arizona after reading all you folks comments. Here is what they said:

Thanks for the heads up. I'll forward this to our technicians.
A few quick things to bring up just for your comfort/knowledge:
A user explained how a cell phone or other equipments GPS isnt affected by powerlines and that can be because of a few different reasons. The biggest one is that most devices are using cell phone towers and triangulation in order to find its position, not multiple satellites. Beyond that, without going into incredible detail, not all electronics have similar components, and thus very different uses, resistances, and weaknesses.
I appreciate you giving us a heads up!

So, Droners, what do you think?
Personally, I will avoid high voltage power lines from now on.
Oh, BTW, I bought Travelers insurance many months ago for my Mavic Pro & they paid the full cost of the $217 repair costs. I had a $50 deductible but they did not apply it to this repair bill - go figure! In case you are interested that is Travelers Indemnity Co. of America.
Appreciate all the comments & suggestions - this is a great website...

I think you should completely ignore most of that. Most devices do not use cell towers for position - they use GPS. And the question of GPS interference is not about the "resistances and weaknesses" of the components - it's about power lines not radiating anything anywhere close to the GPS radio spectrum.

 

[Aerial Gopher]

Well... I wonder why this Mavic was still flying if you can mess it up within 200feet of some big fancy power lines...

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Or Antenna tower ? Meh..... easy flying...

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[ac0j]

I think you should completely ignore most of that. Most devices do not use cell towers for position - they use GPS. And the question of GPS interference is not about the "resistances and weaknesses" of the components - it's about power lines not radiating anything anywhere close to the GPS radio spectrum.

Here we go again....... What do you think the reason is that cell enabled devices HAVE gps chips and NON cellular devices of the same make DO NOT have gps? How would you explain that?
Try reading this....
How does GPS in a mobile phone work exactly?
Yes there IS a GPS chip, BUT it is so tiny and small, it is off most of the time. and is used to double check cell data estimates.

 

[Lon Denard]

Yea but guys inspect power lines using drones all day long.

 

[ac0j]

Yea but guys inspect power lines using drones all day long.

They dont get TOO close. But yes they do. The only thing that might make a difference is if there is a bad connection, and there is a lot of arcing. But in high voltage lines, those turn into complete disconnects before they go on too long.

 

[Lon Denard]

They dont get TOO close. But yes they do. The only thing that might make a difference is if there is a bad connection, and there is a lot of arcing. But in high voltage lines, those turn into complete disconnects before they go on too long.

I don't claim to know how close they get but I do mechanical inspections and I'm guessing they get within the 200' DANGER ZONE....

 

[Lon Denard]

I'm not going the quote the posts but can we clarify that this wasn't DJI telling this guy this crap? People keep saying DJI this and DJI that. It's a store in Arizona with DJI in their name. Also, people that are blaming DJI for this problem when it's not established that this is actually a problem. For all we know, this guy had a loose connection internally, they plugged the GPS module back in and TaDaa!

 

[ac0j]

I'm not going the quote the posts but can we clarify that this wasn't DJI telling this guy this crap? People keep saying DJI this and DJI that. It's a store in Arizona with DJI in their name. Also, people that are blaming DJI for this problem when it's not established that this is actually a problem. For all we know, this guy had a loose connection internally, they plugged the GPS module back in and TaDaa!

From post #23, A note from DJI;


I sent this link to DJI Arizona after reading all you folks comments. Here is what they said:

"Thanks for the heads up. I'll forward this to our technicians.
A few quick things to bring up just for your comfort/knowledge:
A user explained how a cell phone or other equipments GPS isnt affected by powerlines and that can be because of a few different reasons. The biggest one is that most devices are using cell phone towers and triangulation in order to find its position, not multiple satellites. Beyond that, without going into incredible detail, not all electronics have similar components, and thus very different uses, resistances, and weaknesses.
I appreciate you giving us a heads up! "

This is correct. I dont know why people would say this is false. Just people making things up again. Dont believe it? Do you own a Garmin GPS or similar? Does it work inside your house? does it work in the car when not near glass? Probably NOT. BUT the smaller GPS in your phone will, right? Well, not exactly, put your phone in airplane mode, no WiFi and no cell service, then try to navigate. It may know where you were when you shut it off, but it probably wont update if you move. That is exactlty why you MUST BUY A CELLULAR DEVICE to have GPS. AND when flying in airplane mode, your GPS location may be WAY off in DJI go4

 

[designit777]

I just picked up my MP today from "DJI Arizona Powered by Innovative UAS" store located in Scottsdale, AZ. I had it repaired there because the GPS was turning off immediately after takeoff.

This is what was happening. Just prior to takeoff, I would have an RC green take off light & 12 to 16 GPS satellites & a flashing green tail light. Upon takeoff to the 4' altitude the GPS satellites went blank, RC green light turns to caution, & green tail light on Mavic turns to flashing red. I have hovered at 4' for approx 5 minutes with no changes.

I have calibrated the IMU & compass multiple times; I have updated & reinstalled firmware in the RC & Mavic & updated to the latest software on my tablet & phone. I have switched back & forth between the Pixel Xl phone & the Samsung Tab A many times but get the same errors on the drone & my RC. And no, I have not crashed this drone in months & I have taken off from this spot many dozens of times.

The technician at the DJI AZ store, where I got it repaired, told me that I may have flown to close to high voltage power lines after I told him when it first occurred. I remembered that I had been doing a "Follow Me" flight down a dirt road that was near power lines when my MP first started acting erratically. After I brought it home & attempted to fly from my back deck is when I noticed the lost GPS signal & the warning lights. The DJI AZ technician told me to stay at least 200' away from those power lines at all times. He said if you must fly over them, fly 200' above them & do not fly under them because you cannot stay 200' away. He stated that the power lines emitted EMI which 'toasted' the GPS module in the Mavic Pro.

I hope this helps a few of my fellow flyers on this forum...

I once flew very close to some power lines and had no issues. I would not recommend it.

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[DanMan32]

Here we go again....... What do you think the reason is that cell enabled devices HAVE gps chips and NON cellular devices of the same make DO NOT have gps? How would you explain that?
Try reading this....
How does GPS in a mobile phone work exactly?
Yes there IS a GPS chip, BUT it is so tiny and small, it is off most of the time. and is used to double check cell data estimates.

My two Samsung tablets are Wi-Fi only and have GPS. For the last decade Apple is the only one that I know of doesn't equip GPS in devices without cell.
Cell triangulation was done a LONG time ago, and it was not very accurate.

 

[Lon Denard]

From post #23, A note from DJI;


I sent this link to DJI Arizona after reading all you folks comments. Here is what they said:

"Thanks for the heads up. I'll forward this to our technicians.
A few quick things to bring up just for your comfort/knowledge:
A user explained how a cell phone or other equipments GPS isnt affected by powerlines and that can be because of a few different reasons. The biggest one is that most devices are using cell phone towers and triangulation in order to find its position, not multiple satellites. Beyond that, without going into incredible detail, not all electronics have similar components, and thus very different uses, resistances, and weaknesses.
I appreciate you giving us a heads up! "

This is correct. I dont know why people would say this is false. Just people making things up again. Dont believe it? Do you own a Garmin GPS or similar? Does it work inside your house? does it work in the car when not near glass? Probably NOT. BUT the smaller GPS in your phone will, right? Well, not exactly, put your phone in airplane mode, no WiFi and no cell service, then try to navigate. It may know where you were when you shut it off, but it probably wont update if you move. That is exactlty why you MUST BUY A CELLULAR DEVICE to have GPS. AND when flying in airplane mode, your GPS location may be WAY off in DJI go4

So how does my drone know where I am since I use a Crystalsky?

 

[sar104]

Here we go again....... What do you think the reason is that cell enabled devices HAVE gps chips and NON cellular devices of the same make DO NOT have gps? How would you explain that?
Try reading this....
How does GPS in a mobile phone work exactly?
Yes there IS a GPS chip, BUT it is so tiny and small, it is off most of the time. and is used to double check cell data estimates.

You have it backwards. Non-cellular enabled devices typically lacked GPS because the GPS receiver was on the cellular radio chip. Now that's not always the case. Assisted GPS, which I think you are referring to, is where the phone uses cell towers (and sometimes visible wifi networks) to get a rough position (very inaccurate) that speeds up GPS lock, but it's GPS that gives the devices their accurate location data. If you want to test that it is simple - go to a location with no cell service or switch to airplane mode, and you will find that the device GPS is the primary source of location.

 

[sar104]

So how does my drone know where I am since I use a Crystalsky?

Your drone doesn't know, or care, where you are - it just knows about the home point.

 

[DanMan32]

From post #23, A note from DJI;


I sent this link to DJI Arizona after reading all you folks comments. Here is what they said:

"Thanks for the heads up. I'll forward this to our technicians.
A few quick things to bring up just for your comfort/knowledge:
A user explained how a cell phone or other equipments GPS isnt affected by powerlines and that can be because of a few different reasons. The biggest one is that most devices are using cell phone towers and triangulation in order to find its position, not multiple satellites. Beyond that, without going into incredible detail, not all electronics have similar components, and thus very different uses, resistances, and weaknesses.
I appreciate you giving us a heads up! "

This is correct. I dont know why people would say this is false. Just people making things up again. Dont believe it? Do you own a Garmin GPS or similar? Does it work inside your house? does it work in the car when not near glass? Probably NOT. BUT the smaller GPS in your phone will, right? Well, not exactly, put your phone in airplane mode, no WiFi and no cell service, then try to navigate. It may know where you were when you shut it off, but it probably wont update if you move. That is exactlty why you MUST BUY A CELLULAR DEVICE to have GPS. AND when flying in airplane mode, your GPS location may be WAY off in DJI go4

I took you up on that on my HTC 10. The location tracking did work in airplane mode, which did not turn off location services (GPS is passive). I moved about my house and my location did drift. I turned off airplane mode. When I moved about the house, my location didn't move. Google Map's circle of uncertainty didn't change however. Also I have seen location drift indoors without having anytime turned off.
Here's an article about the three ways location services night operate. Note that the article was written in 2011 when not as many devices were designed to have GPS but might still have location services.
How Location Services Work on Mobile Devices - Anders.com

 

[Drgnfli]

I'm not going the quote the posts but can we clarify that this wasn't DJI telling this guy this crap? People keep saying DJI this and DJI that. It's a store in Arizona with DJI in their name. Also, people that are blaming DJI for this problem when it's not established that this is actually a problem. For all we know, this guy had a loose connection internally, they plugged the GPS module back in and TaDaa!

Ahh, NO! Not a loose connection - I had GPS lock on 12 to 16 sats before takeoff, many times & then none at 4' hover...

 

[Lon Denard]

Your drone doesn't know, or care, where you are - it just knows about the home point.

I wouldn't dare argue with you but my display shows my position, the drone's and home point. There's an option to have the drone return to me in a return to home scenario. The Crystalsky has GPS and location settings.

 

[Lon Denard]

Ahh, NO! Not a loose connection - I had GPS lock on 12 to 16 sats before takeoff, many times & then none at 4' hover...

Oh I'm not saying that was it exactly, geez. I'm saying that it could have been anything and they told you some story to mollify you.


BTW how about answering my actual question, was this some random store or was this actually DJI itself telling you this? Everyone seems to be under the impression that you were in contact with DJI.