Traffic information service – broadcast (TIS–B) is an aviation information service that allows pilots to see aircraft that are not emitting ADS-B data but have a basic

transponder In telecommunications, a transponder is a device that, upon receiving a signal, emits a different signal in response. The term is a blend of ''transmitter'' and ''responder''. In air navigation or radio frequency identification, a flight trans ...

. As aircraft are discovered by primary radar and respond with encoded altitude information, this information is broadcast over ADS-B. These near real time positions and

ground track A ground track or ground trace is the path on the surface of a planet directly below an aircraft's or satellite's trajectory. In the case of satellites, it is also known as a suborbital track, and is the vertical projection of the satellite' ...

in 45 degree increments of other nearby aircraft are received as either a "traffic advisory" or "proximate" intruder, for the purposes of collision avoidance. It presents to the pilot a combined representation of aircraft positions derived from GPS satellite and ground-based radar data, specifically: aircraft's replies to ATC interrogations (i.e., they are responses to queries as sent to the aircraft from

air traffic controller Air traffic control specialists, abbreviated ATCS, are personnel responsible for the safe, orderly, and expeditious flow of air traffic in the global air traffic control system. Usually stationed in air traffic control centers and control ...

on the ground). TIS-B is broadcast to aircraft using both the 1090 MHz extended

squitter Squitter refers to random pulses, pulse-pairs and other non-solicited messages used in various aviation radio systems' signal maintenance. Squitter pulses were originally, and are still, used in the DME/TACAN air navigation systems. Squitter puls ...

(1090 ES) and the

universal access transceiver Universal is the adjective for universe. Universal may also refer to: Companies * NBCUniversal, a media and entertainment company ** Universal Animation Studios, an American Animation studio, and a subsidiary of NBCUniversal ** Universal TV, a ...

(UAT) band of

Automatic Dependent Surveillance–Broadcast 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 ...

(ADS-B). Currently the service mainly benefits

general aviation General aviation (GA) is defined by the International Civil Aviation Organization (ICAO) as all civil aviation aircraft operations with the exception of commercial air transport or aerial work, which is defined as specialized aviation service ...

(GA) aircraft equipped with ADS-B "in" hardware by providing a traffic information relay to a screen in the cockpit. In order to use TIS, the client and any intruder aircraft must be equipped with the appropriate cockpit equipment and fly within the radar coverage of a Mode S radar capable of providing TIS. Typically, this will be within 55 NM of these sites. At this time TIS–B is meant to be only a supplement to visual separation from other aircraft when operating in

visual meteorological conditions In aviation, visual meteorological conditions (VMC) is an aviation flight category in which visual flight rules (VFR) flight is permitted—that is, conditions in which pilots have sufficient visibility to fly the aircraft maintaining visual se ...

(VMC) and as a backup to radar, which in remote areas only updates every 13 seconds, when operating under

instrument flight rules In aviation, instrument flight rules (IFR) is one of two sets of regulations governing all aspects of civil aviation aircraft operations; the other is visual flight rules (VFR). The U.S. Federal Aviation Administration's (FAA) ''Instrument F ...

(IFR).}

References

{{DEFAULTSORT:Traffic Information Service - Broadcast Federal Aviation Administration Air traffic control systems