An array of active IR cameras in fixed, known positions, plus IR reflector markers on the UAV works well out of the box over ranges of a few meters. Eg. Vicon. Same tech as motion capture for movies.

I don’t have experience using it in volumes as large as the video, but in moderate sized lab space it works very well, and at high frame rates.

The trick is to invert the problem and have the active sensors off-board and the robot is the (reflected energy) beacon.