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Lost GPS signal

Discussion in 'Pro/Adv Discussion' started by lxldrone, May 24, 2015.

  1. lxldrone

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    Hi all,

    i was flying my dji phantom 3 pro just now, it had GPS lock with 17 satellites but lost GPS signal mid flight (about 50m up) and it started drifting away about 200m. Luckily it regained GPS lock after drifting. do you know what might have caused it? Whats the best way to handle this problem next time?
     
  2. leekiya

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    I have had the same problem. Not a clue why, i was on 1.1.8 at the time what version firmware were you on.
     
  3. lxldrone

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    i was on 1.1.9, first time it happened. I am guessing its because i was in the city, though i was on the outskirts near the beach.
     
  4. blade strike

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    Compass degradation happens.. It should be very rare though.

    Remember you can still fly in atti mode. It switches down automatically. Once the error clears it will switch back to gps.
     
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  5. leekiya

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    Yea i have talked about this in another thread and it might be that my compass got confused with lots of rebar from the sea wall where i took of from, once i flew away from it i got my full lock back. A few people have reported this now tho.
     
  6. lxldrone

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    do you know the main causes for compass degradation?

    i think it was in atti mode, but the wind was fairly strong up there thats why it drifted quite a bit
     
  7. Danderse

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    Compass and GPS lock are two very different parts of the phantom...anything to do with compass should not affect your GOS reciever
     
  8. chris digata

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    But what happens if gps is lost and control signal? will it just hover? will it land where it is? will it fly in the opposite direction to which it just flew to try regain control? or will it climb and try regain gps to rth?
     
  9. alokbhargava

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    If GPS lock is lost, P3 will not be able to maintain its horizontal position and would start drifting. You should immediately switch to ATTI mode and get control of your P3 and get back to home point manually.

    There are low chances of losing GPS lock but it might happen due to following:

    1. Flying near tall buildings
    2. Flying in valleys
    3. P3 top is covered with kind of conducting materials such as CF sheets/ conducting paints resulting into partial EM shields
    4. Electronics malfunctioning
    5. Solar disturbances

    Once the GPS lock is lost, it takes time to get it back and not sure if home point will be retained for RTH. It's better to get down P3 and switch it off and investigate the cause of it. It won't be safe to fly it again at the same location.
     
  10. chris digata

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    Thanks but that was not my question or answered my question.

    THE QUESTION IS.... What will the phantom 3 do if it lost GPS and control signal.. Meaning its on its own..
    will it land where it is? will it fly in the opposite direction to which it just flew to try regain control? or will it climb and try regain gps to rth?
     
  11. bbfpv

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    It would flip to ATTI and drift with the wind. ie, the worst possible scenario for a bird outside of VLOS.
     
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  12. chris digata

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    heh nice one :) But are you saying you think it would just sit there in ATTI in a drift until critical batt and then attempt a land?
    Surely DJI should program the firmware so it went into assend to 100m in a chance to regain the remote signal
     
  13. bbfpv

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    It would only hover in ATTI if there was no wind. If there was even a tiny breeze, it would drift until critical battery and then land. Programming it to ascend to 100m to regain control is a pretty huge gamble considering the wind at 100m can be considerably stronger than closer to the ground. If the control signal was not re-obtained, now the drifting situation went from possible recovery to a highly unlikely recovery.

    btw, this happened to me once w/ a P2V+. You'd be surprised how far they can drift. I ran the numbers based on wind speed and battery left on the day I lost mine, and it wouldn't have gotten to critical battery for approx 6 miles from the HP.
     
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  14. chris digata

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    Thank you for the response BBfpv,, its as i thought and if it happened its time to run as fast as you can toward it in the last chance to give it a cuddle ;)
     
    #14 chris digata, Jan 7, 2016
    Last edited: Jan 7, 2016
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