Compass error while approaching a mountain

[closetmonster]

So, I took off from our campsite (17 satellites) and headed towards a mountainside roughly 1200 ft away (my niece and her friends were climbing it and I decided to send my drone over to get some video). Everything went well until I got close to the hillside when suddenly I received a compass error and I was automatically switched to atti mode. It freaked me out but I was able to somewhat get my composure and bring the drone back safely (calm afternoon, no wind, and had VOS). Does anyone have any theories or a similar experience?

Just FYI I’m flying a P3P, iPhone 8+ latest iOS and latest firmware and software.

Thanks in advance!

 

[With The Birds]

Uploading your flight log from your phone to phantomhelp log viewer and sharing the link back here might allow people to give you a few clues.

 

[solentlife]

As per WtB ... Flight Log can help ..

Just a note : Mountains often contain minerals / ores and it may be that this particular mountain has a high % of Iron Ore or similar. This could in THEORY could cause an error.

Similar to ships ... there are areas marked on Marine Charts ... magnetic anomaly .... often where undersea mountain ranges are with large ore content ... the ships magnetic compass can be affected.... in extreme cases. Not a problem for ships but not so funny for average yachtie where he has no Gyro Compass !!

 

[closetmonster]

As per WtB ... Flight Log can help ..

Just a note : Mountains often contain minerals / ores and it may be that this particular mountain has a high % of Iron Ore or similar. This could in THEORY could cause an error.

Similar to ships ... there are areas marked on Marine Charts ... magnetic anomaly .... often where undersea mountain ranges are with large ore content ... the ships magnetic compass can be affected.... in extreme cases. Not a problem for ships but not so funny for average yachtie where he has no Gyro Compass !!

I was wondering if that might be the case. I will have to do a little detective work and see if I can find out if the composition of the mountain itself is to blame...

 

[solentlife]

If its enough 'ore' to affect your AC ... then a simple hand held compass should deflect as you get nearer ... trouble is that the deflection may be so gradual as you move toward making hard to see. I recc'd an Orienteering Damped Compass... or Marching Compass. Cheap enough in Fishing Shops.
What you need is a visual transit to make sure you are facing / moving same direction. A visual transit is two fixed objects sufficient distance apart so you can visually fix a line. You take compass reading away from the mountain ... then go to the mountain .. take reading again of that transit. Compare the two.

 

[Meta4]

Just a note : Mountains often contain minerals / ores and it may be that this particular mountain has a high % of Iron Ore or similar. This could in THEORY could cause an error.

The only thing a magnetic anomaly would do is make for a little more or less difference between magnetic north and true north.
If there was enough iron ore to cause a compass error, you'd see mining equipment all over the hill, and you'd still have to fly very close to it.

 

[solentlife]

I did say in THEORY ...

But not every mineral rich location gets mined. I bet the Grand Canyon could yield up some interesting profitable material ... but funny that ... no mining there (not that I ever seen anyway)!

I also seem to recall a while back an argument about Magnetic North and relationship to the Drone ... not that I'm arguing.

I also agree that you'd have to fly pretty close ... but again how deep is the ocean when ore deposits there deflect mag compasses ?

I posted the possibility of Ore deposits in the mountain - NOT as a 'sure thing' but purely as a speculative proposal.
My suggestion of the Mag Compass test could throw light on it ...

 

[Tim Haskins]

So, I took off from our campsite (17 satellites) and headed towards a mountainside roughly 1200 ft away (my niece and her friends were climbing it and I decided to send my drone over to get some video). Everything went well until I got close to the hillside when suddenly I received a compass error and I was automatically switched to atti mode. It freaked me out but I was able to somewhat get my composure and bring the drone back safely (calm afternoon, no wind, and had VOS). Does anyone have any theories or a similar experience?

Just FYI I’m flying a P3P, iPhone 8+ latest iOS and latest firmware and software.

Thanks in advance!

Were there any antennas on this mountain such as transmission towers, microwave etc.? Our DJI drones stand up to most transmission towers, cell towers really well these days but there are some antennas that can & will affect anything and everything that comes near them.

 

[Meta4]

but there are some antennas that can & will affect anything and everything that comes near them.

Tower emissions aren't going to have any effect on your compass.

 

[Tim Haskins]

Tower emissions aren't going to have any effect on your compass.

Ok I cant believe you just said that but I am not going to argue the point. I am only a Telecommunications Engineer. What do I know? ha

 

[Meta4]

Ok I cant believe you just said that but I am not going to argue the point. I am only a Telecommunications Engineer. What do I know? ha

If it was true, we'd find drone compasses being affected very much when flying around communications towers.
But we don't.

 

[solentlife]

On the East Coast of UK - there are military early warning electronic arrays ... during the latter part of the Cold War ... I was seismic surveying in the North Sea (I was Marine Crew 'driving the ship' ... ).

When we used to approach that coast line on return to port ... our electronics on board used to play all sorts of games ... VHF radios humming ... nav gear throwing up weird solutions ... in fact we literally resorted to eyeball only and night time approaches were shunned.

There's no knowing what some antenna can do despite being different frequencies etc. To say it cannot happen is optimistic.
The DJI compass is not a mechanical needle sitting on a pin ... its electronic.

 

[Meta4]

There's no knowing what some antenna can do despite being different frequencies etc. To say it cannot happen is optimistic.
The DJI compass is not a mechanical needle sitting on a pin ... its electronic.

Saying .. There's no knowing what some antenna can do, ignores the knowledge we have from millions of flights over the last 6 years.
We aren't back in the drone dark ages where we are scared that anything/everything might possibly cause mischief to our drones.

 

[solentlife]

Dear Tim Haskins ...

Why are you angry with me and giving me a hard time ?? I was supporting you by giving example of antenna and crazy effects far outside their frequencies .........

What did I do wrong ?????

Are you sure you are replying to the correct person / post ?

EDIT : Thanks Tim ... I thought that was what happened ... Phew !!

 

[Tim Haskins]

Dear Tim Haskins ...

Why are you angry with me and giving me a hard time ?? I was supporting you by giving example of antenna and crazy effects far outside their frequencies .........

What did I do wrong ?????

Are you sure you are replying to the correct person / post ?

No no my comment was not aimed at you. I switched to my cell phone and I think I may have replied in the wrong spot. Sorry about that. My reply was meant for Meta4 . That guy gives me grief every time I post on this site.

 

[Tim Haskins]

Saying .. There's no knowing what some antenna can do, ignores the knowledge we have from millions of flights over the last 6 years.
We aren't back in the drone dark ages where we are scared that anything/everything might possibly cause mischief to our drones.

Oh Lord Ok so let me clarify what I said and what I did not say since you’re going to critique everything to your benefit. So I do not know where in the world this person is and there had already been a few suggestions for this issue I decided to add one more possibility for this mountains effect on this guy’s compass. I even stated that DJI drones stand up to most transmission tower and cell towers really well now.

For all I know he could be talking about Cheyenne Mountain and I promise if you fly over that mountain it is very possible that you could have compass issues.
I never said that every tower in the world is a threat to a DJI compass. It does sound like you are saying that NO tower can EVER pose a threat to your DJI compass and I am going to tell you right now that I live near a military tower (that is located nowhere near a military base) that you will not and cannot fly your DJI drone or any other drone within 100ft of it or your drone will hit the ground.

I am not sure why you are so antagonistic towards me but it is your right so carry on if it gives you that much pleasure.

 

[Meta4]

I am not sure why you are so antagonistic towards me but it is your right so carry on if it gives you that much pleasure.

I'm not antagonistic toward you but I'm extremely skeptical of scary maybe, perhaps scenarios without any evidence or examples of how the proposed danger has been demonstrated to be hazardous to drones or in this case, drone compasses.

Drone flying has gradually come out of its dark ages when most flyers knew nothing about how their drones worked and how they would behave and were unnecessarily scared of things that had no effect at all.
You may be a communications engineer, but how much time have you spent flying your drone?
Your hypothesis is that some sort of antenna might have upset the OP's compass.
Have you ever seen an example of a drone compass being affected by an antenna or are you just putting it forward as a "maybe"?

 

[pkozi]

I’ll bet a good directional 2 meter antenna with a ham operator running a 1kw linear could raise a little havoc if bird got close enough

 

[Tim Haskins]

Tower emissions aren't going to have any effect on your compass.

I'm not antagonistic toward you but I'm extremely skeptical of scary maybe, perhaps scenarios without any evidence or examples of how the proposed danger has been demonstrated to be hazardous to drones or in this case, drone compasses.

Drone flying has gradually come out of its dark ages when most flyers knew nothing about how their drones worked and how they would behave and were unnecessarily scared of things that had no effect at all.
You may be a communications engineer, but how much time have you spent flying your drone?
Your hypothesis is that some sort of antenna might have upset the OP's compass.
Have you ever seen an example of a drone compass being affected by an antenna or are you just putting it forward as a "maybe"?

Well of course I was offering this as “maybe” and if you will look back to my comment you will see that I was i’m merely asking “if there were any antennas on the mountain???”

At no time did I say this was absolutely his problem. I just threw it out there as a possibility. You are the only one speaking in “ a matter of fact” or “definitive“ terms.

Now that you are questioning my credibility I will let you know that I have a total of 29 years experience in Telecommunications and I have been a Sr Telecommunications Engineer for the Government since 2007.

I have been flying R/C for about 20 years and drones since 2008. I bought my first NAZA M and built my first Flamewheel in 2009 or 10 then went on to build several other DJI aircraft such as a DJI heavy lift 450 and a 550 using the NAZA MV2 then in 2013ish I built a 700mm heavy lift. I got lazy and stopped building my drones and now I only have three drones. I have a Hubsan X4 Pro H109S High Edition w/ H7000 Android radio, P3P and a P34K.

Now how long have you been flying and where do you get your expertise?

 

[Meta4]

Now that you are questioning my credibility I will let you know that I have a total of 29 years experience in Telecommunications and I have been a Sr Telecommunications Engineer for the Government since 2007.

And in all that time communication engineering and drone flying and building, how many times have you seen compasses affected by communications antennas?
I'm not questioning your credibility, I'm questioning the credibility of the "maybe" hypothesis you threw in to the discussion.
I've seen too many maybes that turned out to be nothings, to take them seriously without more evidence to support the hypothesis.

At this stage of our understanding of drone flying, we need more than "maybe something" or "perhaps something else".
We've had millions of hours of drone flight and some very smart people to help us get a good understanding but as far as I'm aware, we still haven't seen compass effects attributable to emissions from antennas.
We have more evidence to suggest that antenna emissions don't affect drone compasses, than to indicate they are a likely cause.

If you have something concrete to contribute to advance your hypothesis, I'm quite happy to consider it.