I wanted to ask if anyone knows of the best way to either tether a IRIS+ quadcopter so it will hover relatively stationary, or provide a system for indoor navigation for a room. I am currently working on a cyber security research project at a large university, and I have been tasked with having a quadcopter hover in the middle of a large room to provide an aerial vantage point. The building is a former nuclear reactor, so needless to say, GPS is not an option. I have experimented with several different styles of tethers, all of which have lead to oscillations back and forth across the center. The effect is lessened in AltHold mode, but it is still present, and concerning enough that I do not think it is safe for the cyber protection scenario. The eventual goal is that we could either fly the copter around to certain points in the room with an indoor navigation system, use the tether to "pull" the copter to certain points in the room, or have the copter fly in a direction and have the tether keep the range of motion limited enough for stable stationary points in the air. Does anyone have any recommendations? Anything would help, thanks in advance!