Orbiting Eyes: How Space-Based ADS-B Is Revolutionizing Air Traffic Surveillance
Space-based ADS-B became operational in 2019 with Aireon using Iridium NEXT’s 66 low Earth orbit satellites at about 780 km, each carrying an ADS-B receiver listening at 1090 MHz and delivering data to ground stations with latency under 1.5 seconds and updates often in the 2–5 second range. Before 2019 only about 30% of the globe had ADS-B surveillance and roughly 70% of airspace lacked real-time coverage, whereas space-based ADS-B now provides global coverage including oceans and the poles. On March 27, 2019, NAV CANADA and NATS deployed space-based ADS-B in the North Atlantic, reducing lateral separation from about 40
