Electronics experimenter Simon Aubury has recently made a write up on his blog about a project he has been working on. His project is the use of a Raspberry Pi with servo mounted video camera and RTL-SDR to automatically track and record video of passing aircraft.
Simon’s project works by using the RTL-SDR connected to the Raspberry Pi as an ADS-B receiver. From the ADS-B signals the current coordinates of nearby aircraft can be determined. Then by using some coordinate math, the Raspberry Pi can be told to point its camera in the direction of the aircraft. As well as videoing the passing aircraft, the Raspberry Pi also overlays text on to the video showing information such as flight number, source and destination airports, aircraft type, elevation and distance and date of observation.