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Error: High GPS HDOP

Discussion in 'X8+ Help' started by Drone-Survey-Photography, Jul 22, 2015.

  1. Drone-Survey-Photography

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    I was flying when I lost visual sight of the X8+, large trees and sunlight at about 300 feet out 50 feet altitude. I activated RTL and a few seconds later back it came, hovered, perfect landing. The throttle was down so it shut down. Since then I have not been able to arm. I get a cheery tone then a flashing yellow light, two flashes, pause two flashes pause. Connected Mission Planner and get High GPS HDOP, this during precheck.

    What is this and what is the cure,

    Thanks
     
  2. Ian [P13]

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    It's a poor GPS lock, make sure you're not taking off with nearby obstructions, trees, houses etc. Give the GPS enough time to lock. HDOP needs to be below 2 to take off, in simple terms it's a measure of the quality of the GPS lock...
     
  3. Adimuzio513

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    Can't say it's the same for sure but here the past week my solo has had a very hard time getting locked and has shown a higher hdop than normal consistently. I've had to go to manual and take it up a ways before it finally gets back to normal again. So I've been taking off and landing in manual only for the time being I also would love to know why this has suddenly changed, after the update I was fine then this happened a week or so later.
     
  4. Drone-Survey-Photography

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    The High GPS HDOP is an bigger issue, I found some good information on Cloud-surfer.net and ardupilot.com will be trying out some of the information. Adimuzio has one of the cures that have been propose and there are some setting that can be reconfigured.
     
  5. Adimuzio513

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    Please post or keep me updated on what you find while manual flight works fine now it's still not the ideal solution, as soon as it gets gps locked it switches over to fly and makes me nervous since sats are in and out. The distance to home jumps all over and I'm worried the auto switch is going to make solo itself do the same one of these times. Hdop is definitley the big issue and even with 11 or 12 sats I've seen as high as 4.0 hdop still so seems that fix would probably take care of all the other gps issues were seeing. Sometimes it locks at 7 other times it won't at all even showing 12 or 13 satellites.
     
  6. Drone-Survey-Photography

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    I removed the fence and that cured my issue. You may give it a try. HDOP is 4.5
     
  7. Adimuzio513

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    So what fence did you mean in tower I'm guessing? What's it labeled as, is it just your distance or altitude limit fence or something else? Just seems odd that it would affect the gps issue but if it did I'll try anything seems like mine got worse today I was a hundred or more feet above every tree around with 12 sats before I finally got locked just a minute ago. Starting to make me wonder if something's broke or burning up already, hope this fix works on solo as well thanks.
     
  8. jpowerhouse

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    I get this same error. I live out in the country and start the drone with no apparent obstructions.
     
  9. Drone-Survey-Photography

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    The fence is a distance at which a RTL will be issued automatically, I am using mission planner and it is part of the setup, the default is 350 m. The concept is the GPS is needed in order to determine if you are flying too far, so it issues and error when the Hdop is high. My Hdop has been about 2.2 (the error occurs over 2) and I am getting plenty of satellites, there are some other. Since removing the fence I lock onto enough satellites to fly in just a few seconds, it took a couple of minutes before.

    See if you can fine the RTL safety measures and what the settings are. These include the Fence, loss of signal, low battery, etc.
     
  10. Drone-Survey-Photography

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  11. Mazzoo

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    I have the same issue. Any fix?
     
  12. Drone-Survey-Photography

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    See my post above,, I eliminated the fence and have not had any issues. I believe you can also increase the HDOP mine see to be just a little over, but I have not tried that yet. One thing I did notice it is ready to fly much sooner, needs fewer satellites to fly.