ADS-B receivers are electronic devices that listen for radio signals from ADS-B aircraft transponders and decode them to determine aircraft positions. FlightAware has created an open-source software solution called PiAware to make aircraft data accessible to everyone. PiAware uses low-power hardware like a Raspberry Pi, a Pro Stick (an inexpensive USB adapter), and an antenna to receive signals from aircraft. Together, the software and hardware decipher and display the 1090MHz ADS-B data in SkyAware, FlightAware’s web-based map interface that allows users to view aircraft positions on a local network. The receiver also sends the data to FlightAware to provide and improve free flight tracking on flightaware.com.