Maybe I can get GPS data but I don't think it's accurate enough. A few feet wrong would show the wrong position of the drones. It is important to be able to see who is currently the number 1, 2, 3 in the race.
OK let's say I have cameras, how do I get the data x/y/z for each flying object?
For viewing I'm thinking some kind of 3D engine. The view can look like a game, it does not need very beautiful graphics just be clear about what is happening in realtime.