Concept
Automatic Dependent Surveillance–Broadcast (ADS-B) is a surveillance technology and form of Electronic Conspicuity in which an aircraft determines its position via satellite navigation or other sensors and periodically broadcasts it, enabling it to be tracked. The information can be received by air traffic control ground stations as a replacement for secondary surveillance radar, as no interrogation signal is needed from the ground. It can also be transmitted and received point-to-point by other aircraft to provide situational awareness and allow self-separation. ADS-B is "automatic" in that it requires no pilot or external input. It is "dependent" in that it depends on data from the aircraft's navigation system. ADS-B is being incorporated in various jurisdictions worldwide. It is an element of the United States Next Generation Air Transportation System (NextGen), the Single European Sky ATM Research project (SESAR), and India’s Aviation System Block Upgrade (ASBU). ADS-B equipment is mandatory for instrument flight rules (IFR) category aircraft in Australian airspace; the United States has required many aircraft (including all commercial passenger carriers and aircraft flying in areas that required a transponder) to be so equipped since January 2020; and, the equipment has been mandatory for some aircraft in Europe since 2017. Canada uses ADS-B for surveillance in remote regions not covered by traditional radar (areas around Hudson Bay, the Labrador Sea, Davis Strait, Baffin Bay and southern Greenland) since January 15, 2009. Aircraft operators are encouraged to install ADS-B products that are interoperable with US and European standards, and Canadian air traffic controllers can provide better and more fuel-efficient flight routes when operators can be tracked via ADS-B. ADS-B, which consists of two different services, "ADS-B Out" and "ADS-B In", could replace radar as the primary surveillance method for controlling aircraft worldwide.
