Airport Surface Detection Equipment, Model X, or ASDE-X, is a runway-safety tool that enables air traffic controllers to detect potential runway conflicts by providing detailed coverage of movement on runways and taxiways. By collecting data from a variety of sources, ASDE-X is able to track vehicles and aircraft on airport surfaces and obtain identification information from aircraft transponders.
The ASDE-X data comes from surface movement radar located on the air traffic control tower or remote tower, multilateration sensors, Automatic Dependent Surveillance Broadcast (ADS-B) sensors, the terminal automation system, and aircraft transponders. By fusing the data from these sources, ASDE-X is able to determine the position and identification of aircraft and transponder-equipped vehicles on the airport movement area, as well as aircraft flying within five miles of the airport.
Controllers in the tower see this information presented as a color display of aircraft and vehicle positions overlaid on a map of the airport’s runways, taxiways and approach corridors. The system creates a continuously updated map of the airport movement area that controllers can use to spot potential collisions. This technology is especially helpful to controllers at night or in bad weather when visibility is poor.
ASDE-X Safety Logic (AXSL) is an enhancement to the situational awareness provided to air traffic controllers by ASDE-X. AXSL uses surveillance information from ASDE-X to determine if the current or projected positions and movements of aircraft or vehicles that are being tracked present a potential collision situation. Visual and audible alerts are provided to the controllers that include critical information about the targets, such as aircraft identification and where aircraft and vehicles are on the surface.