Automatic dependent surveillance

{
  "id": "MLC-T-AVN-000158",
  "term": "Automatic dependent surveillance",
  "field": "Aviation and air traffic control",
  "definition": "1. BROADCAST (ADS-B)- A surveillance system in which an aircraft or vehicle to be detected is fitted with cooperative equipment in the form of a data link transmitter. The aircraft or vehicle periodically broadcasts its GNSS-derived position and other required information such as identity and velocity, which is then received by a ground-based or space-based receiver for processing and display at an air traffic control facility, as well as by suitably equipped aircraft.\n\n2. REBROADCAST (ADS-R)- A datalink translation function of the ADS-B ground system required to accommodate the two separate operating frequencies (978 MHz and 1090 MHz). The ADS-B system receives the ADS-B messages transmitted on one frequency and ADS-R translates and reformats the information for rebroadcast and use on the other frequency. This allows ADS-B In equipped aircraft to see nearby ADS-B Out traffic regardless of the operating link of the other aircraft. Aircraft operating on the same ADS-B frequency exchange information directly and do not require the ADS-R translation function.",
  "synonyms": [
    "ADS [ICAO]"
  ],
  "see_also": [
    "Automatic dependent surveillance-broadcast in (ADS",
    "Automatic dependent surveillance-broadcast out (ADS",
    "Cooperative surveillance",
    "Global positioning system (GPS)",
    "Space-based ADS-B (SBA)"
  ],
  "references": [
    "FAA Pilot/Controller Glossary"
  ],
  "url": "https://mlchart.com/terminology/aviation/automatic-dependent-surveillance/"
}