ADS-B is an improvement of aircraft surveillance systems in which onboard electronic equipment automatically broadcasts, every half-second, aircraft data via a digital data link.
The broadcasted data can be used by other aircraft and air traffic control to show the aircraft’s ID, position, altitude, velocity (and other data) on display screens without the need for ground radar. Dedicated ADS-B ground stations receive the broadcasts and relay the information to air traffic control for precise tracking of the aircraft.
ADS-B depends on accurate position and velocity data from the aircraft’s navigation system (e.g. GPS).
As a summary, ADS-B acronym is self-evident:
- Automatic – no pilot input or external interrogation.
- Dependant – depends on aircraft’s navigation system accuracy and integrity.
- Surveillance – Provides aircraft position, altitude, velocity, and other surveillance data to anyone that requires the information.
- Broadcast – Information is globally and continually sent.
ADS-B is transforming aviation : real-time precision, shared situational awareness, advanced applications for pilots and controllers brings aircraft surveillance to a next step, helping safety and efficiency to improve. ADS-B-equipped aircraft and vehicles exchange information on one of two frequencies: 978 MHz or 1090 MHz. Onboard “Mode A/C” and “Mode S” transponders, as well as Traffic Collision and Avoidance Systems (TCAS), use 1090 MHz. ADS-B extends the message elements of Mode S, adding information about the aircraft and its position. This extended squitter is known as 1090ES, which is the preferred ADS-B standard for flights above 18,000 feet.