TL;DR
Przemek Wasinski has created an automated plane-spotting system that combines a software-defined radio with a motorized camera. This setup tracks aircraft using Automatic Dependent Surveillance-Broadcast (ADS-B) technology, which allows planes to continuously broadcast their location and other data. By using a 1090MHz radio antenna and decoding the signals with a tool called Dump1090, Wasinski's system can plot aircraft positions on a radar-like map.