About 5 years ago I started trying to build this exact thing. I wrote some code, printed some gears and attached them to servos, assembled some hall effect sensors onto the whole thing, and then stopped. I had a camera that I could command to an azimuth and an elevation. I think it was a PlayStation3 pseye camera. It certainly would not have been able to zoom in to the point that this one seems to be able to. I was going to use my RTL SDR to listen to the ADSB and mount the whole thing on my roof under a clear plastic dome.