The US FAA has launched a new technology dubbed the wide area augmentation system (WAM) at Juneau airport in Alaska.
WAM allows air traffic controllers to track aircraft along the difficult approach to the airport, where radar coverage is not available.
Using WAM controllers now see aircraft approaching Juneau, a capability not previously available due to the rugged terrain surrounding the city.
The mountains around Juneau make it impossible to use radar coverage, which resulted in controllers using large distances to separate aircraft on approach to the airport. Through WAM, air traffic controllers can now safely decrease aircraft separation to 5nm.
WAM features a network of small sensors deployed around Juneau that emit signals that are received and sent back to aircraft transponders.
The system triangulates the returning signals to determine the precise location of each aircraft, enabling controllers to see those aircraft on their screens as if they were radar targets.
FAA says WAM is pegged for near-term use in Juneau while the agency deploys automatic dependent surveillance broadcast (ADS-B) nationwide in 2013. After that time WAM will serve as an ADS-B backup in the event of GPS outage.
ADS-B uses GPS to transmit an aircraft's position, speed and altitude to controllers, and in some cases to other aircraft.
Another WAM system is operating in Colorado, says FAA.
Source: Air Transport Intelligence news
