Analysis of operational data gathered from the FAA's Capstone experiment in Alaska has persuaded the agency that the aircraft position-reporting performance of automatic dependent surveillance broadcast (ADS-B) is better than that provided by radar.
A memorandum sent by the leader of the FAA's Oceanic & Offshore Integrated Product Team, Nancy Graham, to the manager of the agency's Flight Technologies and Procedures Division on 30 November gave an unequivocal thumbs-up to the accuracy of ADS-B's position-finding and the timeliness of its reporting.
"After a thorough review of the data, I am pleased to advise you that the ADS-B reported positions displayed to the air traffic controller appear to be as good as or better than the Anchorage radar data for determining aircraft position, speed and direction of flight," writes Graham.
"Furthermore, there is no significant evidence of track stitching in ADS-B target reports by comparison with radar target reports," she continues in her memorandum.
""In summary…the accuracy, frequency and reliability of the ADS-B data appear to be superior to radar as a source of aircraft surveillance information," reports Graham.
She concludes: "I recommend Flight Standards consider issuing a notice approving use of Capstone ADS-B data as an aircraft surveillance source as good as or better than radar for the Bethel, Alaska area."
In the Capstone experiment, general aviation aircraft fitted with advanced avionics have been reporting ADS-B position data automatically to the Anchorage Air Route Traffic Control Center (ARTCC). The Anchorage ARTCC controls much of Alaska's airspace as well as a large amount of North Pacific airspace.
"This is a major finding that really clears the way for the certification of ADS-B for IFR separation and air traffic control," says a spokesman for UPS Aviation Technologies, the manufacturer of much of the datalinking and display hardware used by aircraft in the Capstone experiment.
Sister company UPS Airlines is the pioneer of ADS-B use, having now certificated ADS-B for use in a conflict-alerting mode on the flightdecks of its Boeing 727 freighters.
"Everything appears to be on track for the January 1 certification of radar-like services using ADS-B" for Capstone, says the UPS spokesman.
He adds that the real significance of the FAA's Capstone findings about ADS-B is that "this is the first time in 53 years - since the 1947 advent of radar - that the FAA will have certificated a new surveillance method, one that is an end-to-end solution".
When ADS-B is certificated for use with the Micro-EARTS en route and terminal radar system used by the Anchorage ARTCC, it can be used with Micro-EARTS anywhere else. The UPS spokesman points out that Micro-EARTS is used elsewhere in the USA and internationally.
Even more significant, UPS is now working to achieve full operational certification within the next two years the use of ADS-B with the ARTS-3E terminal radar made by Lockheed Martin.
Lockheed has already achieved an ADS-B receive capability in shadow mode with the ARTS-3E used at Louisville, UPS' base.
The UPS spokesman says the significance of certificating ADS-B for full operation with the ARTS-3E terminal radar is that the system is used to control the terminal airspace areas of Atlanta, New York, Washington DC, Chicago, Los Angeles and San Francisco. These are the busiest areas of airspace in the USA and, indeed, in the world.