Airline flights are being closely tracked and directed without radar for the first time in the nation's history as part of a new system monitoring the skies above the Colorado Rockies.
The program is a look ahead to the way air-traffic controllers may soon monitor planes across the USA. It uses similar technology to the satellite-based system that the Federal Aviation Administration (FAA) is installing nationwide to replace radar over the next decade, said Vincent Capezzuto, who oversees the agency's modernization technology.
Capezzuto said the idea is "all part of the big picture" in planning for future generations of air-traffic control and for trying to reduce flight delays.
The new system uses 20 sensors clustered around four airports within the Rockies. The sensors monitor radio broadcasts from planes. By measuring minute differences in the time it takes for the broadcasts to reach the various sensors — as slim as 10 billionths of a second — computers can determine a plane's location, said Ken Tollstam, vice president of Sensis, which built the devices.
Since the 1950s, radar has been the backbone of the air-traffic system, allowing controllers to monitor the growing number of flights and prevent mid-air collisions. But its technical limits have made airports inefficient, leading to flight delays. The government plans to shift to a more accurate satellite-based tracking system by 2020.
Experts said the success of the Colorado program, which was certified for use by controllers last month, is a sign that the technology underpinning the satellite system can work.
"It's a major shift in how we do business and it is one of the beginning signs that we are modernizing the system," said John Hansman, a Massachusetts Institute of Technology professor who studies air-traffic issues.
Though it had never been used to guide planes in the air in this country before, the technology behind the Colorado system has been used at dozens of airports to track planes on the ground.
