Evidence that the ground infrastructure for Automatic Dependent Surveillance-Broadcast (ADS-B) is taking shape can be found next to a conference room at the ITT Advanced Engineering & Sciences offices in Herndon, Va.
In an adjacent room, a retractable window blind opens to reveal ITT’s Network Operations Center, where several ITT and AT&T personnel sit at computer terminals before an oversized, split-screen display. At the center of the display is a map of the United States with ADS-B implementation sites represented as colored icons, concentrated in the Northeast and Florida. To the right is a ground station status window and a similar window for Automated Weather Observing System (AWOS) installations; to the left is a view of FAA’s monitoring system to compare notes with what the agency is seeing and a window for CNN television, to keep abreast of the world outside.
ITT representatives emphasize that the “NOC” was built to monitor and troubleshoot the radio-station infrastructure, not to control it. The center is staffed 24/7 by technicians who analyze event messages and resolve automated trouble tickets. “It’s connected to the network, but not on the critical path. It’s not on the service provision path,” explained David Stewart, a consultant with Capital Sciences LLC, who led a recent tour of ITT’s facilities for a contingent from Avionics Magazine.
Nevertheless, the cleverly concealed ops center is impressive as an embodiment of the progress made toward nationwide deployment of ADS-B. While national attention has been focused elsewhere since the ADS-B contract was awarded in August 2007 on a change in presidencies, on the greatest economic crisis since the Depression, on the conflicts in Iraq and Afghanistan ITT’s industry team and FAA have moved the chains on a fundamental shift in aviation from ground radar-based air traffic control to satellite-based air traffic management.
South Florida was the first region commissioned for ADS-B service, in November 2008. Last December, ADS-B “critical services” the presentation of downlinked ADS-B targets on controller displays were activated at the Houston Air Route Traffic Control Center, making surveillance available of overflying airliners as well as low-flying helicopters supporting the offshore oil industry in the Gulf of Mexico. Initial operational capability of ADS-B critical services at the Philadelphia Terminal Radar Approach Control (Tracon) was anticipated as this issue of Avionics went to the printer.
“The milestones drive the program,” said Glen Dyer, ITT’s ADS-B program manager, describing the workmanlike pace. “They create focus and clarity.”
Piecing together the network backbone has been less publicized. As of February, ITT had stood up control centers in Ashburn, Va., Dallas and Anchorage. The control centers, co-located with AT&T data centers, receive and process aeronautical weather information from WSI Corp. for Flight Information Service-Broadcasts (FIS-B), air traffic information from FAA for Traffic Information Service-Broadcasts (TIS-B) and ADS-B targets from the ground stations, which are fused with radar data for the TIS-B service. The centers also host the Automatic Dependent Surveillance-Rebroadcast (ADS-R) function of translating and retransmitting 1090ES messages from large aircraft to smaller aircraft equipped with 978 MHz Universal Access Transceivers, and vice versa. Trade studies were being conducted to site further control centers at points on the West Coast and in the Pacific.
FAA cites its own progress in assessing and signing-off ADS-B services and facilities. In addition to certifying the new system, the agency has to adapt its air-traffic control automation platforms for Tracons the legacy Common ARTS and new Raytheon Standard Terminal Automation System (STARS); for enroute centers the Lockheed Martin Enroute Automation Modernization (ERAM) system to accommodate ADS-B messaging.
“We’re really proud of what we’re doing. We’ve got a good team,” Vincent Capezzuto, FAA director of Surveillance and Broadcast Services, said in a recent interview. “It’s the entire FAA; this is not a singular entity doing this. It requires close coordination with our safety group, the air cert people, the flight standards people. Tech ops has to do the certification all the different factions within the FAA really need to pull together. We have the support of the NextGen office … right up to the administrator.”