ADS-B
Automatic dependent surveillance-broadcast (ADS-B) is a surveillance technology for tracking aircraft as part of the Next Generation Air Transportation System (NextGen).[1] The United States will require the majority of aircraft operating within its airspace to be equipped with some form of ADS-B Out by January 1, 2020.[2]
Description
ADS-B, which consists of two different services, "ADS-B Out" and "ADS-B In", will be replacing radar as the primary surveillance method for controlling aircraft worldwide. In the United States, ADS-B is an integral component of the NextGen national airspace strategy for upgrading/enhancing aviation infrastructure and operations. The ADS-B system can also provide traffic and government generated graphical weather information through TIS-B and FIS-B applications.[3] ADS-B enhances safety by making an aircraft visible, realtime, to ATC and to other appropriately equipped ADS-B aircraft with position and velocity data transmitted every second. ADS-B data can be recorded and downloaded for post-flight analysis. ADS-B also provides the data infrastructure for inexpensive flight tracking, planning, and dispatch.[3]
The system relies on two avionics components—a high-integrity GPS navigation source and a datalink (ADS-B unit). There are several types of certified ADS-B data links, but the most common ones operate at 1090 MHz, essentially a modified Mode S transponder, or at 978 MHz (USA only).[3] The FAA would like to see aircraft that operate below 18,000’ use the 978 MHz link since this will help alleviate further congestion of the 1090 MHz frequency.[4] To obtain ADS-B capability at 1090 MHz, you can install a new transponder or modify an existing one if the manufacturer offers an ADS-B upgrade. You will also need to add a certified GPS.[3]