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Comment by tgflynn | Hacker News Reader

Multiview cameras.

Once you have the tracking data how do you plan to view it ?

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.

If you have 2 cameras observing the same object and you know their coordinates and orientations in 3D space there's a fairly simple algorithm to recover 3D coordinates from pairs of matching pixels between the two images. It should be covered in most computer vision textbooks, such as the Szeliski book: https://szeliski.org/Book/. Of course you also need an algorithm for matching pixels between the two images. There are a number of ways of doing that, also covered in the book. OpenCV probably has code that would help with some or all of this.

> For viewing I'm thinking some kind of 3D engine.

OK, that makes sense, I just wanted to be sure we were talking about the same thing.

EDIT: BTW I assume that you don't have access to the data from the drones themselves. If you did it would probably be much easier just to capture GPS coordinates from them.

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.

The biggest source of inaccuracy in GPS are atmospheric effects, meaning two receivers in the same vicinity see similar errors. If you get the drone's GPS position and compare it to the reported GPS position from a stationary receiver planted nearby you might be able to get enough accuracy to be useful (basically a poor man's differential GPS).

> It is important to be able to see who is currently the number 1, 2, 3 in the race.

So in addition to finding the current position of the racers you'll also need some history to determine where they are on the track. You'll also need to define the path of the track in order to determine the rank.

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