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A discussion about UAV Pilot Depth Perception (PDP)

Discussion in 'Inspire 1 Discussion' started by Transpire, Aug 21, 2015.

  1. Transpire

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    I wanted to open a discussion about UAV Pilot Depth Perception.
    As I hone my skills, I have come to the very strong conclusion that as a human being, with my eyes only several inches apart, that depth perception falls off dramatically beyond 20-30 feet. My primary reason for bringing up this topic is not for ABSOLUTE depth perception, but rather, RELATIVE depth perception. This is an important distinction.

    ABSOLUTE depth perception would be the ability to determine the actual distance from yourself to your aircraft with an acceptable margin of error.

    RELATIVE depth perception would be the ability to determine the difference in distance between your aircraft and objects in the foreground and background.

    Here is an example....
    You are flying at a low altitude (below the tree line) in a large field. The field is surrounded by tall trees. You are standing at one end of the field and the aircraft is at the far end of the field. Let's say 300 feet away. I have found it very difficult to judge the RELATIVE distance between the aircraft and the trees. What might appear to be 20 feet could actually be 100 feet and, vice versa, what could appear to be 100 feet could actually be 20 feet.

    Another real life example....
    A car is parked at the curb at the end of the street. There is a stop sign behind the car. Is the stop sign 20 feet or 100 feet behind the car?

    As I train to become a better pilot, I find PDP to be the most difficult aspect of flying overall. It is a similar effect to the "compression" effect that results from using a very long photography lenses (300, 400, 500, 600mm) in photography. The far field objects and near field objects become compressed so as to confuse the viewer as to the relative distance between them.

    I would like to hear you guys weigh-in on this phenomenon and how you have handled it to allow for safe flying....
     
    Ascender likes this.
  2. lake_flyer

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    You are absolutely right.
    Flying VLOS is very difficult. That's why most first timers immediately get an FPV capable drone. They will probably never learn proper VLOS flying because they think they don't have to.
    It takes a lot of practice and those who have a long experience in flying RC model aircraft in the days FPV was not available, have an advantage in that.

    But even with a 3D simulator, on a 2D computer screen, you should be able, after long and frequent practise, to determine relative distance.

    Most people, starting for the first time with flying, will never allow themselves to get the VLOS flight hours and experience, needed to get the bird under control in every situation. When the FPV fails, they're just lost.
     
  3. RGD

    RGD

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    I can speak to this issue from personal experience. Several weeks ago at our company picnic I flew the I1 into a tree accidentally because of this effect. I was shooting a volleyball game and thought my flight path was clear of the tree and wham. I am not sure if googles would help or not. Even with googles you sort have limited peripheral vision. I am a pilot also and I can't imagine trying to land a plane with limited peripheral vision. I suspect that most of the military UAV guys land with autopilot. I would like to talk with one of those guys or gals.
     
  4. The Editor

    The Editor Moderator
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    No - Reapers are not allowed to land/take-off under autopilot (not with a bazillion tonnes of warfare on board :p).
    Flight control is handled by the guys in Las Vegas but there is a two second delay between control input and control surface response. This just would not work for take off and landing so control is handed over locally to a flight crew (usually 30 minutes out) and a local pilot lands the AC via remote.
     
  5. Transpire

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    Hey Guys,
    Thanks for the replies!
    My goal for bringing up this topic is to ultimately improve my skills. At 50 yo, I agree wilth lake_flyer and I am of the mindset that flying VLOS is a very important skill set. Especially with a 7+ pound object flying around. Call me old school...

    So, the situation that RGB describes is EXACTLY the situation that I want to avoid, especially after a few near misses and since relying solely on FPV seems, dare I say, irresponsible. I can't imagine solely relying on the FPV aspect of this, as it appears to be like a video game, but with the added risk of a device that can do damage to person and property.

    So, I would almost like to rephrase my post to include a request for advice as to how best to improve this skillset? How does one improve the PDP to a point that there is much more confidence with near field and far field relative distances? Any recommended practice maneuvers?

    Interestingly, I had a conversation with my father about this. He knows nothing of this industry or of RC. He is, however, a golfer!
    What in the world does that have to do with anything you ask? Well, on golf courses, this depth perception confusion is typically addressed with a tree or marker of some sort planted/positioned at a known distance to the hole. So I thought of doing something similar for practice. Setting up markers of known distance from me to fly past and through for practice.

    Thoughts?
     
  6. IrishSights

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    I too a while back de-leafed part of a tree branch, but stayed aloft. I was only 100m out. It was a test flight at a remote field and I had no observer with me that day.

    This is why under UK CAA rules an observer is a requirement with my setup with good reason. As well as watching for approaching people, other aircraft, etc he is another set of eyes for approaching trees :)
     
  7. The Editor

    The Editor Moderator
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    This is an interesting topic and something that flyers come across daily.
    For the very reasons mentioned is why standard UK CAA permissions are limited to 500m distance from the pilot and 400ft agl
    Even at those distances orientation and depth perception (the two biggest causes of crashes) can become an issue.
    There are tips and tricks you can pick up along way like always making sure you can see air (daylight) between your aircraft and an obstacle or the horizon. Getting used to the field of view from the camera and gauging distance. You can practice this by setting up an obstacle like a chair or table etc only a few feet away from you (say 20 feet)- something you can judge the scale of. Then fly up to it as close as you dare WITHOUT looking at your screen so totally line of sight. You can even walk up behind your Inspire to see exactly how close you are hovering to your object.
    Then and only then, look at the screen and see how it appears via the camera feed. (It will always look further away!!!!!). Do this a lot until you feel comfortable doing it in reverse, ie, flying up to an object without looking up at your Inspire, then check your distance by line of sight.
    You will slowly get more confident judging proximity from what you see on the screen and get used to flicking your eyes from the screen to the aircraft constantly.
    And....don't fly too fast, remember, if you are moving, there is a lag between what you see on the screen and where your aircraft is positioned in real space.
     
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  8. Scotflieger

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    The large military UAVs are flown by 2 sets of pilots. The first set takeoff and land manually are based in a tent or cabin at the operating base communicating via the UAVs own radios with local ATC. The second set can be on the other side of the world (in Nevada or Lincolnshire) and fly the main missions via satellite links but also communicating with local ATC using the UAV radio. The reason for the 2 sets of pilots is that the latency via satellite is too great to safety fly the UAV during the takeoff and landing phases. The data latency is where it takes about a second for a signal to travel from the ground to a geostationary satellite and back down again. There could be multiple satellites involved and many seconds delay in sending a command and the same again to see the response.