FAA has chosen the 1090MHz Extended Squitter (1090ES) and the Universal Access
Transceiver (UAT) technologies as its respective data link standards for
airline/high altitude and general aviation users of Automatic Dependent
Surveillance-Broadcast (ADS-B) position reporting.
1090ES standard to be used by airlines is based on the Mode Select (Mode S)
surveillance radar standard and technology developed in the early 1990s. The
UAT technology was developed by the US government’s Mitre Corporation from the
mid 1990s and incorporated into production units by UPS Aviation Technologies
for the Capstone ADS-B experiment in Alaska.
they form two out of three potential ADS-B data link technologies the FAA has
been studying since 1992, the third being the VHF Data Link Mode 4 (VDL Mode 4)
first developed in Sweden in the late 1980s.
working independently for several years, the FAA and the Radio Technical
Committee on Aeronautics (RTCA) cooperated to form the ADS-B Link Evaluation
Team in December 1998. This later evolved into the joint FAA-Eurocontrol
Technical Link Assessment Team, formed to develop inter-operable standards for
the ADS-B networks under separate development in the USA and Europe.
FAA intends to install the ground infrastructure for ADS-B to enable coverage
throughout the entire US National Airspace System (NAS) from 2007 to 2012. This
will allow ADS-B air-to-ground surveillance and ground-to-air uplink broadcasts
to be carried out using the 1090ES technology for high-altitude,
high-performance aircraft and the UAT technology for general aviation aircraft.
position reporting by aircraft will provide improved air traffic control
surveillance for controllers, giving them each aircraft’s call sign, position,
velocity, positional intent and other factors.
turn, the ground network will broadcast to each aircraft the ADS-B-derived
positions and multilateration-derived Traffic Information Services-Broadcast
(TIS-B) positions of all the other aircraft in its vicinity. This will give
pilots a much greater degree of situational awareness of traffic in their
vicinity and will help to improve the efficiency of usage of the NAS by giving
closer controls of functions such as departure and arrival spacing.