Unlike a traditional airborne radar which follows an aircraft by bouncing off of it, ADS-B (Automatic Dependent Surveillance-Broadcast) is an active communication between an aircraft and its ground-based sensors. ADS-B uses 1090MHz frequency to transmit data in standard form to ground facilities, which can then independently determine the aircraft’s location and speed. This system is mandatory for large planes in Europe and the United States. Its implementation is scheduled for 2020 and 2023.
ADS-B is a relatively new function in the aviation world, having first been implemented in the United States in 2005. There are two main subsystems in the ADS-B function. First, there is the transmitter. This sends data out to ground facilities. Second, there is the receiver. This receives the data from the transmitter. These subsystems provide information on aircraft, including speed, altitude, and any other relevant data to ground-based facilities. The transmitter represents the core of the system. ADS-B is also capable of intercepting position reports from other aircraft. It can also be used for improving air traffic control by displaying aircraft position in real-time. This is not possible with other types of surveillance.
There are many ADS-B systems available, but the most widely used is the TACAN. There are other systems such as the FLARM which is not compatible ADS-B and the TACAN-G which is slower and more costly. FLARM is one of the most fascinating systems. It can be used for tracking gliders and light aircraft. However, the system is not compatible with ADS-B, making it a poor choice for gliders. ADSB is far more reliable and provides both information on aircraft movements on the ground as well as in the air. It is also a very effective means of surveillance.
There are many versions of ADS-B, the most recent being ADS-B 3.0. Although the name may seem clunky at first, many countries have already adopted ADS-B, including France, Japan and the United States. ADS-B signals can also be heard from the ground as well as in the stratosphere. Although not required, ADS-B is the functional equivalent of a flight data recorder, and is also capable of intercepting and recording position reports from other aircraft. It has been a boon for airtraffic control, but has also been controversial. Some pilots argue that the system is a hindrance to safety, especially when it comes to flying gliders and other light aircraft.
