The US Federal Aviation Administration was an early adopter of multilateration when it launched its ASDE-X program in 2000. The system fuses returns from a primary surface radar with data from an array of multilateration sensors around an airport to provide a complete picture of surface movements. The system is currently being installed at 35 leading US airports, replacing earlier, non-multilateration radar systems. ASDE-X also incorporates a predictive multilateration program to alert controllers of potential conflicts between surface traffic and approaching aircraft.


Colorado, one of America’s leading winter vacation destinations, has launched a state-wide multilateration program to dramatically increase access to ten mountain airports. Poor radar coverage had imposed 30 NM buffers” between approaching aircraft, resulting in excessive delays and cancellations. Purchasing traditional radars to adequately cover each airport was estimated at $7 million per radar, excluding installation and maintenance, for a total of $70 million. Small, high accuracy multilateration stations covering all airports, and bringing 5-mile approach separations, will total $15 million. Colorado is purchasing the equipment, with the FAA assuming ownership, operation and maintenance after commissioning.

Aspen Airport