WASHINGTON - One of the technologies being used to reduce the potential for collisions is a runway-safety tool called ASDE-X. ASDE-X is a critical element in the United States Federal Aviation Administration's (FAA) mission to increase runway safety.

ASDE-X enables air traffic controllers to detect potential runway conflicts by providing detailed coverage of movement on runways and taxiways. ASDE-X collects data from a variety of sources to track vehicles and aircraft on the airport movement area and obtain identification information from aircraft transponders.

The ASDE-X data is derived from surface movement radar located on the air traffic control tower or remote tower, multilateration sensors, ADS-B (Automatic Dependent Surveillance-Broadcast) 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 is an enhancement to the situational awareness provided to air traffic controllers by ASDE-X. It 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 the potential for collision. 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.

The first use of the ASDE-X system was at the General Mitchell International Airport in Milwaukee, Wis. in October 2003. The ASDE-X Safety Logic system enhancement was first implemented at the Orlando International Airport in Florida in January 2006. With the exception of a few retrofits to the initial sites, Safety Logic was implemented at the majority of the ASDE-X sites during initial installation. All ASDE-X sites have the Safety Logic system enhancement. The FAA began using the 35th and final ASDE-X system at the Memphis International Airport in Tennessee in June 2011.

Source: U.S. FAA
Associated URL: http://www.faa.gov/news/fact_sheets/news_story.cfm?newsId=17095
Author: U.S. FAA