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Best Way to Use DJI GO to Aim TX with Directional Antenna at P3P

Discussion in 'Pro/Adv Discussion' started by GadgetGuy, Nov 24, 2015.

  1. GadgetGuy

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    What is the best way to use DJI GO telemetry to make sure a directional antenna is pointed and aimed directly at the P3P, when not flying directly away from or towards the transmitter?

    With only a 60° angle to play with at long range, it is critical that the spherically polarized antennas on the latest antenna mods are always pointed facing the aircraft, no matter which direction it is flying. When flying in a straight line away, or a straight line towards the transmitter, it's easy: keep the head of the red arrow facing the center of the radar or pointing straight up. However, when you are flying laterally, and can't see any landmarks to align yourself with, what's the best way to immediately repoint the transmitter at the aircraft, after losing signal, based upon the last telemetry displayed? All help appreciated!
     
    #1 GadgetGuy, Nov 24, 2015
    Last edited: Nov 24, 2015
  2. alokbhargava

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    If you lose the signal RTH will be automatically triggered. If signal is present, you can lock home and pull it back.
     
  3. GadgetGuy

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    Indeed, but that destroys my video continuity and first sends it up to 400 feet above my launch point (based upon my settings), and starts bringing it back home, when I want to keep going, losing valuable flight time, and ruins the mission. The only reason for loss of signal is my failure to keep the antenna properly aimed at the aircraft when flying laterally. I want to avoid the signal loss in the first place, by using the telemetry, to make sure I am always directly pointing the very directional antennas at the aircraft. The signal loss is not gradual and monitorable like with the stock antenna. The signal goes from 100% to 0% almost immediately. Right now, I keep changing the direction manually, and hope to reacquire it before RTH kicks in. Any other ideas?
     
  4. III% Streve

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    Just keep the radar so that YOU in the center are pointed toward the P3.. white tick mark at the top. The green cone is theoretical RF signal
    Capture.PNG
     
  5. GadgetGuy

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    Thank you! That's very helpful! What does it mean, though, if the red arrow is not in the center and is outside the concentric circles? How do I get it back into the center, or does that even matter, as long as the two vector signals are facing each other? I guess I never noticed the tiny P3 tick mark triangle before.
    I'm going to be looking very closely for it now! :cool:
     
  6. PVFlyer

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    FPV Camera app might be an option. It's designed for distance flyer with better navigation map and pilot wand to help aiming directional antenna easier.

    [​IMG]
     
    III% Streve likes this.
  7. GadgetGuy

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    Thanks! That's just what I need. However, for now, I'd like to stay with DJI GO. Is it possible to easily task switch between the two apps in flight, say when I really need the pilot wand? Also, is there a distance radius limitation from the Home Point launch location in setting up your waypoints in the Mission Planner add on? Can I specify and fly to a waypoint located 5 miles from my launch point, or are they limited to the same 1500 meter (that's what I recall from memory) radius parameters as the DJI GO waypoints?
     
    #7 GadgetGuy, Nov 24, 2015
    Last edited: Nov 24, 2015
  8. lotusteve

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    the concentric rings are for distance from you, the further you fly away the further the red (phantom) arrow goes away from the center.all i do is keep turning my body so the little white marker at the top is allways in line with the red arrow. the green cone is for which direction the camera is pointing on the inspire,(as far as iam aware) the inspire has a 360deg camera. the go app is used for phantom and inspire.
     
  9. FredzMaxxUAV

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    DJI Go has a radar screen (see above) AND a line pointing to the bird. How is FPV Camera then better?
    Will you add a radar screen soon?
     
  10. GadgetGuy

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    That's very helpful, as well. So, in the photograph above, of the DJI GO radar, thoughtfully provided by III% Streve, the labels of "P3 Location" and "You" are actually reversed? That makes sense in a way, as the white marker (moi) never moves, while the red P3 arrow does, but it is still confusing!
    So, since two points always make a straight line, how are you making a unique line which lines up the transmitter and the aircraft with the little white marker and the red arrow? Is it the point end of the red arrow that you are making face the little white marker, or the tail end, or the white beam from the white marker? So, confusing as it may be, the point of the red arrow must always point at the little white marker, and not at the center of the concentric circles? Is that true no matter which direction the nose and the camera of the P3P are pointing?

    The camera and the nose of the P3P always are facing the same direction, but the flight heading can be altered from the camera direction, just like on the Inspire1. So, the green cone isn't necessarily the direction of flight.
     
  11. GadgetGuy

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    So, here's what I have come with. The radar alone won't help. You have to also use the map which shows a green "pilot wand" connecting the aircraft to the home point which is the location of the transmitter. The map in the full screen view can be centered on the aircraft location or the home point using the icons. If the map is unlocked (away from North being up), and the map is then centered on the aircraft, one can then turn in the direction of the aircraft using some as yet undetermined combination of the red arrows and the compass. If nothing else, the green line can then be followed back to some visible landmark in the foreground to point the transmitter at. However, there still must be a better way. Anyone?
     
  12. lotusteve

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    this is how i use my radar.. stand with the phantom in front of me then take off, with my feet in the same spot as take off, fly the phantom forward and lets say to the right of me.
    you will see the red marker move away from the center to up and right on the radar,now turn your body so the white marker and the phantom are back in a line from white marker to center of radar. now you are facing your phantom again,when coming home my red arrow will point to the middle (only if i turn the phantom round and fly home forwards not backwards) for a quick test put your phantom on your garden and switch on,stand behind about 2 meters away from it and turn your body holding the remote (note the white marker) now turn back to face your phantom and the white marker will be back inline.or if you are using a ipad try this out in the simulator.
     
  13. PVFlyer

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    FPV Camera combines both radar and map into a single view navigation map. The auto-zoom also maintains both aircraft and home/pilot point in the map all time. Check out the OP video for reference DIY Antenna Booster for Phantom 3 | DJI Phantom Forum
     
  14. GadgetGuy

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    Excellent! I'll explore this in detail on my next flight! It's important to get it right. The simulator suggestion is an excellent one, too, as I use an Air 2! Thank you, and thanks to everyone else, who contributed, too! :D
     
  15. GadgetGuy

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    Can you please also answer my questions to you, above in the thread, after your first post about your app? I'm interested, but need those questions answered.
     
  16. Chris P Duck

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    My radar always seems to be off by about 20degrees clockwise.
    It's consistent so I can use it but is always off.

    I checked by flying as far as I could away while maintaining sight (easier at night) then pointing the remote at the bird and looking at the radar.
     
  17. PVFlyer

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    You can switch between DJI and FPV apps, but it's not recommended. You will get an incomplete flight log in the app for sure after switching.

    There is no distance limit in setting up waypoints, but you got to know what you are doing. There is a preliminary calculation to tell you the estimate of total travel distance, maximum waypoint distance, time & battery required, etc.

    [​IMG]

    You can set a waypoint 5 miles away, but I bet a low battery RTH will kick in when you reach 2.5-3 miles away to abort the mission and RTH for safety reason.
     
  18. GadgetGuy

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    That's great news! All the other Mission apps I have looked at for iOS cripple waypoints by refusing to set them more than 1.5 km away, if not closer! I have a battery mod that gives me 25 minute flight times, and a transmitter mod with a 7+ mile range, so 10 mile flights are no problem, and automating a repeated flight to a landmark 5 miles away would be awesome. I also have the smart battery return disabled in DJI GO and critical battery is set to 10% with low battery set to 15%. Smart Go Home is way too conservative, leaving 30% remaining battery upon landing, which is a huge waste of invaluable flight time. May I assume your app doesn't independently create its own low battery returns, and simply adopts whatever DJI GO settings are stored on the aircraft? I assume one can abort any mission and resume manual transmitter control by switching from F mode to P-GPS or ATTI mode, while retaining FPV through either HDMI out on transmitter or relaunching DJI GO? The only thing that concerns me is your FAQ which suggests recycling the aircraft to reconnect may be necessary, if signal is lost upon aborting a mission! That certainly wouldn't be possible with the aircraft in the air 5 miles away! Care to comment upon when and why that might be necessary? Thanks!
     
    #18 GadgetGuy, Nov 24, 2015
    Last edited: Nov 24, 2015
  19. GadgetGuy

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    Wow! That's disconcerting! I wonder if a new compass calibration would correct that. Maybe the IMU is off, too. Theoretically, compass and IMU calibrations should align everything accurately, unless I am missing something else.:confused:
     
  20. PVFlyer

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    Low battery RTH is set to flight controller, regardless which app do you use. You may use DJI GO to configure it, while FPV Camera doesn't have the UI to do so. You may abort the mission by flipping to P-mode on RC, and you can keep flying manually within Mission Planner or Camera instead of switching to DJI GO. If RC signal lost during mission, the mission will continue as planned.