Good day! I have a full complect of DJI A2 Flight Controller, and I need to use my octocopter indoors - under the ground. Room is ~20*20*5 meters. Of course, because of several floors and roof on top it's no GPS signal in that room. But in that room we have own source of coordinates: on ceiling we have a lot of cameras, which can track position of anything. We already tested it on on-ground robots and this system gives good coordinates: +-5 cm. Also, we have in that room ultrasonic positioning system, which accuracy is good too. Is there any possible variants to send coordinates of drone from that systems on A2 Flight Controler? Wi-Fi, Bluetooth, Radio channel, etc? We just need to use cool features of A2, like return to the place of take-off, etc. I will be very grateful for any help.