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UNDERSTANDING COMPASS AND MAGNETIC FIELDS

PB30X

PB30X

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http://gps.ece.cornell.edu/SpaceWeatherIntro_ed2_10-31-06_ed.pdf

http://copter.ardupilot.com/wiki/common-appendix/automatic-compass-declination/

****If anybody would like to add, by all means PLEASE DO!! And make this a STICKY PLEASE!!****

Seems to be allot of misunderstanding/misinterpretation of calibrations when, and why they should or SHOULD NOT be done! Instead of arguments of who's RIGHT or WRONG.. Now you decide and Learn for your own SAKE and SAFETY. Google Search Works wanders[emoji6]

COMPASS SENSE goes a long ways[emoji13]
 
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PB30X said:
http://gps.ece.cornell.edu/SpaceWeatherIntro_ed2_10-31-06_ed.pdf

http://copter.ardupilot.com/wiki/common-appendix/automatic-compass-declination/

****If anybody would like to add, by all means PLEASE DO!! And make this a STICKY PLEASE!!****

Seems to be allot of misunderstanding/misinterpretation of calibrations when, and why they should or SHOULD NOT be done! Instead of arguments of who's RIGHT or WRONG.. Now you decide and Learn for your own SAKE and SAFETY. Google Search Works wanders[emoji6]

COMPASS SENSE goes a long ways[emoji13]
Click to expand...
Great couple of documents - thank you.
First one might be a little daunting and probably a difficult read for some. Bubble theory!!!!
Basically, for our purpose, space weather CAN affect GPS accuracy but as long as you keep an eye on what's going on and probably do not fly with anything over a kp index of 5 you should be fine.
Second document, gives some good guidelines as to the minimum distances items can have an influence on the compass!

Have stickied this thread.
 
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My first post...
I have had 95 flawless flights on my I1....until yesterday. This thread caught my attention because yesterday I had my first "hard landing" and I was really confused at first as to what might have caused it. I had just flown it about a mile away with no issues. Drove to new location and launched it. Immediately after takeoff it started drifting. Was acting like it was in ATTI mode with a wind, however it had a great GPS signal and did not appear to change modes. It was very loose on the controls and concerned me (since I was near a lake). I tried to set it down, but with the excessive drifting side load it flipped over on its side. It only chipped 2 prop tips but also cracked a carbon fiber arm which I have repaired (for now) and it is flying normal again. Hurt my pride more than the craft.

My question to you guys is, there was a thunderstorm pretty close...actually really close I'll admit. It was an isolated cell that was cruising by real fast. I was way out in the clear and it was moving away from me but I wondered if the electrical energy in the storm had effected this? The other thing I noticed was I failed to fold out the antennas into the proper position and didn't notice since they were behind my iPad. Any chance this could have caused it? The I1 never got more than 50' away from me though.

This is my 3rd DJI product. I admit complacency may be setting in. I've went so long without any problems that I've started to take this amazing little machine for granted. I just flew the last 2 weeks with it in Hawaii and it was exilerating to fly there. Sure glad this didn't happen while I was standing out on the lava rocks cruising it over the Pacific!

Any thoughts from you guys (The Editor in particular)? Thank you!
 
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Great posts guys!

@MoxieSky - Firstly, welcome to my forum!

Did you calibrate the compass before any of the 2 flights? Did you happen to look at your MOD values prior to taking off? If yes, what were the readings?

Next time this happens to you please switch to ATTI and immediately try and land her safely and then check your mod values.
 
Yes, I did a compass calibration he flight prior (about a mile away). I don't normally calibrate it before every flight, however I had just relocated it about 4000 miles so I definitely was going to. I failed to check MOD values before the flight (admit I was getting complacent) but I did a few minutes after the incident and they were normal. I will definitely switch to ATTI mode next time hopefully if this ever happens again, I think I was in shock that I was suddenly loosing control and just tried to get it on the ground immediately.
 
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sirnikolas said:
Great posts guys!

@MoxieSky - Firstly, welcome to my forum!

Did you calibrate the compass before any of the 2 flights? Did you happen to look at your MOD values prior to taking off? If yes, what were the readings?

Next time this happens to you please switch to ATTI and immediately try and land her safely and then check your mod values.
Click to expand...


YOUR forum eh? :p
 
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MoxieSky said:
My first post...
I have had 95 flawless flights on my I1....until yesterday. This thread caught my attention because yesterday I had my first "hard landing" and I was really confused at first as to what might have caused it. I had just flown it about a mile away with no issues. Drove to new location and launched it. Immediately after takeoff it started drifting. Was acting like it was in ATTI mode with a wind, however it had a great GPS signal and did not appear to change modes. It was very loose on the controls and concerned me (since I was near a lake). I tried to set it down, but with the excessive drifting side load it flipped over on its side. It only chipped 2 prop tips but also cracked a carbon fiber arm which I have repaired (for now) and it is flying normal again. Hurt my pride more than the craft.

My question to you guys is, there was a thunderstorm pretty close...actually really close I'll admit. It was an isolated cell that was cruising by real fast. I was way out in the clear and it was moving away from me but I wondered if the electrical energy in the storm had effected this? The other thing I noticed was I failed to fold out the antennas into the proper position and didn't notice since they were behind my iPad. Any chance this could have caused it? The I1 never got more than 50' away from me though.

This is my 3rd DJI product. I admit complacency may be setting in. I've went so long without any problems that I've started to take this amazing little machine for granted. I just flew the last 2 weeks with it in Hawaii and it was exilerating to fly there. Sure glad this didn't happen while I was standing out on the lava rocks cruising it over the Pacific!

Any thoughts from you guys (The Editor in particular)? Thank you!
Click to expand...

Welcome to the forum.

KP index was high yesterday so you may have experienced more drift than usual even in GPS mode http://www.tesis.lebedev.ru/en/magnetic_storms.html
 
Maxwell's Equation...? What the...? :confused:

Well, that certainly took the fun out of flying an Inspire 1 for a moment. o_O

Postings such as that should come with a warning, like...
WARNING: The following link contains deep scientific theory containing advanced partial differential equations that, together with the Biot-Savart law, form the foundation of classical electrodynamics as it pertains to the magnetic field on the axis of a current loop.​

The point being: If you can understanding that warning, then knock yerself out, click on the link and continue reading.

For those of us who are totally clueless as to what the heck they're talking about, then click here.
 
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On the first link from the OP, if you scroll past all those word looking things, and the math type stuff, there are pretty pictures :)
 
PB30X said:
This really isn't an app, but it works well

http://www.uavforecast.com
Click to expand...

Hmm. The forecast KP Indices do not seem to match up with n3kl.org (the NOAA site). Yesterday we had a major storm (don't think I've seen KpIndex = 8 before), though. Bear in mind this is UTC, so for Pacific Time we're -8 hours. Each bar is 3 hours.

noaa_kp_3d 2015-06-23.gif

However compare the above with uavforecasts:

uavforecast 2015-06-23 2236 PDT.png

Uavforecasts.com seems to be able to forecast KpIndex for 2015-06-24 through to 2015-06-30 -- which is interesting. I wonder where that forecast data is coming from.
 
I really don't understand why the compass is blamed so much, Most instruments that use compass and gps the compass is only needed when standing still as soon as you move, from the GPS reading the computer knows you moved from point a to point b so it not only knows what direction it is heading but how fast you are traveling. There is so much out there that can affect a compass reading that it seem silly that it should be relied upon so much.
 
Hi Richard
This magnetic storm will interfere with your compass, your GPS positioning and your RC radio transmission.
If it did only interfere with the compass then I would agree with you, unfortunately it interferes with many other electronic devices as well.
Rgds
David
 
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