Welcome to PhantomPilots.com

Sign up for a weekly email of the latest drone news & information

Ground station start altitude anomaly

Discussion in 'DJI Ground Station' started by Buckaye, Sep 8, 2014.

  1. Buckaye

    Joined:
    Aug 24, 2014
    Messages:
    1,557
    Likes Received:
    420
    Location:
    Orlando
    Hey guys -

    I think I mentioned this in another post - but I really saw a stark example this weekend - wondering if any of you are seeing it as well.


    I have an iPad GS latest firmware on everything with a Phantom 2 Zenmuse setup with go-pro.

    When I initially get communication set up with the Phantom in it's take-off position it reads an altitude of about 10 ft (sitting on the ground)

    THEN - I take off and fly it through several waypoints and land...

    when I look at my GS getting ready for the second mission - the altitude now reads ~30 ft... sitting in the same spot as before.

    I believe this is what caused my crazy flight about 8 days ago (setting it for 30 feet and it flew closer to 2 to 3 ft off the ground)


    Has anyone else seen this? The GS reads one altitude on the ground for the first flight and then a second altitude on the ground for subsequent flights? (on more piece of info - both flights I had about 12 satellites - don't know if that matters).
     
  2. Suwaneeguy

    Joined:
    Feb 19, 2014
    Messages:
    701
    Likes Received:
    22
    Had the same thing happen.
    Set for 30 feet but flew at about a foot above the ground.
    Even though the dials were showing 0 at startup.
    Hasn't happened again.
     
  3. tbwester

    Joined:
    Jul 1, 2014
    Messages:
    80
    Likes Received:
    2
    I think it has to do with the ground model they use, and maybe some other stuff as well. I don't know how it calculates height, but it doesn't use the starting point as zero - because I have never seen it read zero at the starting point.

    I give things a wide berth - 100 feet vertically - when I program it. Its just a limitation of the technology.
     
  4. Buckaye

    Joined:
    Aug 24, 2014
    Messages:
    1,557
    Likes Received:
    420
    Location:
    Orlando
    Thanks guys... that's the response I was expecting... I was just surprised at how much it changed between the beginning and end of the flight... but it certainly explains my low altitude debacle the other week :)
     
  5. EMCSQUAR

    Joined:
    Sep 5, 2013
    Messages:
    1,692
    Likes Received:
    6
    Location:
    N 44.895 W 93.354 Minnesota
    It tends to read more accurately 30+ft away from Tx also.
     
  6. Buckaye

    Joined:
    Aug 24, 2014
    Messages:
    1,557
    Likes Received:
    420
    Location:
    Orlando
    huh... that's interesting... I'll test that out too! Thanks :)
     
  7. TNdrone73

    Joined:
    Sep 11, 2014
    Messages:
    1
    Likes Received:
    0
    I have had a similar issue except it always reads between -10 to -30 ft while on the ground.
     
  8. tbwester

    Joined:
    Jul 1, 2014
    Messages:
    80
    Likes Received:
    2
    I flew from the top of a tall building, and the start "ground" level was set to near zero.... So that answers that question.

    Also, It had an error of about 20 feet. I was able to go above and below the start point, and at about 20 feet below it read zero - if that makes sense.