Automatic Dependent Surveillance–Broadcast (ADS–B) System

 Automatic Dependent Surveillance–Broadcast (ADS–B) is a modern tracking technique that combines an aircraft’s positioning source, aircraft avionics, and a ground infrastructure to create an accurate tracking interface between aircraft and ATC. ADS–B is a performance–based tracking technology that is more precise than radar and consists of two different services: ADS–B Out and ADS–B In.

ADS-B Out works by broadcasting information about an aircraft's GPS location, altitude, ground speed and other data to ground stations and other aircraft, once per second.  ADS-B In provides operators of properly equipped aircraft with weather and traffic position information delivered directly to the cockpit.