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Starting Altitude - Ground Level vs Sea Level

Discussion in 'Pro/Adv Discussion' started by paulsluxmd, Sep 30, 2015.

  1. paulsluxmd

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    I live at 600 feet above sea level. I have a Phantom 2 Plus and a Phantom 3 and have noticed that the Phantom 2 Plus flights always start at altitude above sea level, while the Phantom 3 makes it starting point at ground level. These are Flytrex maps but I have confirmed on the Phantom 3 log directly from the drone. Anyone seeing the same or is there something wrong with the Phantom 3 or the Flytrex?? Is there a way to adjust to altitude above sea level??

    Phantom 2 Plus

    Screen Shot 2015-09-30 at 6.55.31 AM.png

    Phantom 3

    Screen Shot 2015-09-30 at 7.05.02 AM.png
     

    Attached Files:

  2. Meta4

    Meta4 Moderator
    Staff Member

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    No Phantom has any idea where sea level is.
    The only height they know is home = zero.
     
  3. bbfpv

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    Both the P2 and P3 use AGL. Not sure what's going on w/ the Flytrex on your P2.
     
  4. Chris P Duck

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    If you have an actual flytrex unit it knows sea level. If you're just exporting the phantoms own logs onto flytrex's site it won't know so both will show as the same.
     
  5. paulsluxmd

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    That's ingesting because both maps shown are directly from the Flytrex Live website data and map that the connects from the 2 units. Do you think the new Flytrex Live Plus isnt able to detect sea level??
     
  6. bbfpv

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    To be clear, the Flytrex itself does not do any detection of altitude. It simply relays what the FC is saying and posts it to the Flytrex servers. Purely speculation but it's possible the Flytrex servers are doing the cross reference between your GPS coords and the corresponding sea level based on info from google maps, and maybe the algorithm changed btwn the P2 and P3 version of the tracker. The birds certainly don't have that information on hand (as far as I am aware).
     
  7. N017RW

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    I too wonder how they do that?

    Maybe it's too early but without correcting for current surface atmospheric pressure AMSL seems a bit dubious.

    Anyone else can explain a method?