Welcome to PhantomPilots.com

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

What happens if you fly from a cliff?

Discussion in 'Pro/Adv Discussion' started by movius, Jan 17, 2016.

  1. movius

    Joined:
    Jan 11, 2016
    Messages:
    153
    Likes Received:
    45
    I've asked a few dumb questions here so this one should come as no surprise! Thanks to all those that humour (and help) me learn.

    So, I live on the coast. If I'm flying from a ground zero location at the top of a cliff, how does the P3P respond once it clears the cliff edge if I've set say "fly at 10m". Does it plummet down after it clears the cliff edge until it's 10m above the beach / sea / rocks or does the internal barometer sort it all out?

    As I said, it's probably a dumb question but one that's stopping me capturing some cracking images and video of this beautiful region.

    Advice appreciated.

    Regards
    David

    Sent from my SM-N9005 using Tapatalk
     
    Wolfiesden likes this.
  2. Rumbaar

    Joined:
    Dec 27, 2015
    Messages:
    261
    Likes Received:
    43
    Location:
    Melbourne, Australia
    The drone is "dumb" and zero ground level is where you've taken off. So over the cliff it'll fly at the same 10m as if over ground where you started. So you'll be a lot higher from AGL under the drone and go into negative height when you descend.

    It doesn't and cannot see how high it is, in real time. It's just the barometer from start point.
     
    movius likes this.
  3. m0j0

    Joined:
    Dec 26, 2015
    Messages:
    1,536
    Likes Received:
    530
    Aircraft logs takeoff point as ground level (GL) the aircraft will remain at that point until you land. So if you fly it at 10m AGL it will remain at 10m AGL (take off point).
     
    movius likes this.
  4. emilewski

    Joined:
    Mar 26, 2015
    Messages:
    47
    Likes Received:
    13
    Location:
    Manchester, CT
    Not a dumb question at all, as I wondered the same thing as a newbie. But now I can say I have done it many times and no issues. The height you take off at is 0. When you go over the cliff edge it will stay level and still be 5 feet or whatever your altitude was. If you descend below the cliff then you will have a negative altitude reading.
     
    dhsprogis, movius and Gary M like this.
  5. Gary M

    Joined:
    Jan 16, 2016
    Messages:
    464
    Likes Received:
    132
    I asked a similar question yesterday and got pretty much the same answer as you just gave. Except for the "negative altitude reading" part. Glad you mentioned that. That would be an interesting surprise to see the altitude reading at -100' or something, lol!
     
  6. Phantomfreak

    Joined:
    Dec 12, 2015
    Messages:
    196
    Likes Received:
    70
    I have had mine to -185 feet negative altitude, no issues..
     
    andy238 likes this.
  7. movius

    Joined:
    Jan 11, 2016
    Messages:
    153
    Likes Received:
    45
    Thanks guys. It's reassuring to know that it isn't gonna plummet 40 odd meters towards some very nasty looking rocks. Next good flying day, I'm off to give it a go.

    Sent from my SM-N9005 using Tapatalk
     
  8. robby3265

    Joined:
    Sep 9, 2015
    Messages:
    65
    Likes Received:
    21
    Check out this cliff video
     
  9. Gary M

    Joined:
    Jan 16, 2016
    Messages:
    464
    Likes Received:
    132
    AWESOME video Robby! My wife loved it too.
     
    robby3265 likes this.
  10. happydays

    Joined:
    Jul 5, 2013
    Messages:
    1,858
    Likes Received:
    663
    Location:
    Warrenpoint, Ireland
    To the OP - you usually get some great photos and video :D:D:D:D:D
     
  11. alokbhargava

    Joined:
    Sep 28, 2015
    Messages:
    5,158
    Likes Received:
    1,665
    Location:
    San Francisco, CA
    It's true that it takes the ground zero as the starting point. You should judge the wind velocity at the cliff, sometimes it's so high that it would be difficult to control your drone there. Be careful
     
    movius likes this.
  12. happydays

    Joined:
    Jul 5, 2013
    Messages:
    1,858
    Likes Received:
    663
    Location:
    Warrenpoint, Ireland
    The problem with trying to watch a clip like this in 4K is the broadband speed. I tried watching in 4K, but just kept getting the spinning dots of death. I'm on about 37 Mb/s download speed here which generally isn't bad.
     
  13. TheTrickster

    Joined:
    Dec 30, 2015
    Messages:
    31
    Likes Received:
    7
    It was my first time this weekend going 'below' were I took off - I did wonder if it would shut the motors off if the altitude was 0m or below... alas it kept on flying :)
     
  14. impilot51

    Joined:
    Dec 3, 2015
    Messages:
    405
    Likes Received:
    147
    Yeah, would love to watch it but can't get it to play at all. I have plenty of data, but my LTE connection must be too slow. Do you have a lower res version you could post? Perhaps HD?


    Sent from my iPhone using PhantomPilots mobile app
     
  15. Wolfiesden

    Joined:
    Jan 12, 2016
    Messages:
    1,187
    Likes Received:
    400
    Location:
    Milwaukee, WI, Ft Walton Beach, FL
    The only dumb question is the one never asked.
     
    Steve Wilcox likes this.
  16. Wolfiesden

    Joined:
    Jan 12, 2016
    Messages:
    1,187
    Likes Received:
    400
    Location:
    Milwaukee, WI, Ft Walton Beach, FL
    I have to ask...why is it there?
     
  17. robby3265

    Joined:
    Sep 9, 2015
    Messages:
    65
    Likes Received:
    21
    The video is on YouTube if you care to view you can lower quality on there, search user name, abovethebirds ler ,
     
  18. Wibble

    Joined:
    Feb 7, 2015
    Messages:
    1,313
    Likes Received:
    478
    Location:
    Brecon Beacons Wales UK
    I get 1mb - yes seriously! With 2 lines bonded together!
    TooWay Satellite broadband was awesome for the first 3 months 24m connection. Now they cap it to 512k during the day it is a complete joke. Hopefully BT are going to give us fibre to the house as they are doing a rural trial. If so I will get 300mb!!!
     
  19. MichaelR

    Joined:
    Aug 17, 2015
    Messages:
    69
    Likes Received:
    11
    Ok, here is a question that I think is perfectly valid, but it maybe dumb to some.....
    On a previous thread some time ago I was suggesting features/improvements that could possibly be incorporated into the next (or future) models i.e. Phantom 4 etc.
    I would like a 'real-time' barometer feature like in real aircraft. The reading from Start point is great....but i would also like an accurate AGL reading whilst in flight too. Would this extra feature be too costly or complex for a circa £1,200 copter?
     
  20. Rumbaar

    Joined:
    Dec 27, 2015
    Messages:
    261
    Likes Received:
    43
    Location:
    Melbourne, Australia
    This is the only way a drone could maintain a 400' AGL constant and be enforceable as a restriction. Currently it's not a constant definable attribute during flight.
     
    MichaelR likes this.