By David Jensen
HERNDON, Va., 30 June 2010. In late September a major milestone for the Automatic Dependent Surveillance-Broadcast (ADS-B) ground infrastructure will be reached when prime contractor ITT Corp. in Herndon, Va., completes Segment 1 of Federal Aviation Administration's (FAA's) infrastructure program. Adopting a performance-based acquisition philosophy, FAA awarded ITT a $1.86-billion contract to build, manage and maintain theADS-B ground infrastructure through 2025. ITT had 90 ground stations operational in late May and will have 300 installed -- largely in the East Coast, upper Midwest, Alaska, and West Coast -- by September. Each ADS-B ground system includes a closed cabinet in which two racks support multi-channel transceivers, data communication, and systems monitoring equipment, along with a battery for short-term power. Next to the cabinet is an engine generator for long-term power. Segment Two of the deployment program, which runs from this year to 2013, will see all of the about 800 ground station installed and ADS-B coverage nationwide. After in-service validation testing is completed, the system will then be approved as a surveillance system for controller use and for ADS-R (Rebroadcast). In-service validation testing is took place at four key sites -- Louisville (IOC in October 2009), Gulf of Mexico (IOC in December 2009), Philadelphia (IOC in February 2010), and Juneau, Alaska (IOC in April 2010). ADS-B data at these sites will be merged and compared with radar data to check on the system’s accuracy for safe aircraft separation and other applications. ADS-R is a sort of automated translating service that assures all ADS-B-equipped aircraft see all other ADS-B equipped aircraft, regardless of the data link they are using. The technology has the ground system receive 1090ES messages and rebroadcast them as UAT messages, and vice versa. In addition, FAA has asked ITT to complete East Coast coverage by installing two additional ground stations in Canada, in Nova Scotia, and on Sable Island, about 100 nm off Nova Scotia’s southeast coast. "With two more radios, we can gain 500 extra miles of surveillance on the East Coast," says Vincent Capezzuto, ADS-B program manager in FAA's Surveillance and Broadcast Services Office. "It's an aggressive schedule, but we've hit all the milestones," says John Kefaliotis, referring to the ADS-B ground infrastructure program. Kefaliotis is ITT's vice president, Next Generation Transportation Systems. September will be a banner month for ITT. In addition to completing close to half the nation's ADS-B ground infrastructure, it also plans to complete deploying the AWOS (automated weather observing system) in the Gulf of Mexico. AWOS data will be integrated into FAA's weather network. Now, the helicopter pilots flying IFR to offshore oil and gas rigs in the Gulf can more accurately plan their fuel for diversions in IMC conditions. ITT deployed 27 AWOS systems as of late May and will have nine installed by September. To accommodate airborne activity surrounding the April 20 BP oil-spill disaster, the U.S. government has sought to have the weather sensors activated and part of FAA's weather network as soon as possible. The AWOS network will complement the ADS-B infrastructure in the Gulf of Mexico, which, when completed later this year, will have 12 "ground" systems on offshore platforms and nine systems on shore. The network of systems feed traffic data to the Houston (Texas) ARTCC. FAA's focus on improving communication, navigation, and surveillance in the Gulf of Mexico is understandable. More than 650 helicopters, one of the world's largest concentrations of rotorcraft, fly back and forth to some 5,500 offshore oil and gas production platforms, logging approximately 2.1 million operations annually. These operations extend 250 miles off the coasts of Texas, Louisiana and Mississippi, and at low altitudes, are well out of radar range. In addition to the ground systems, ITT was contracted to furnish ADS-B control stations and two network operations centers. Two control stations -- in space rented from AT&T in Ashburn, Va., and Dallas, Texas -- process data from all the ground stations for target validation. This is done by comparing ADS-B data from multiple ground stations and with radar inputs. ITT plans a third control station on the West Coast, Kefaliotis says. A decision of its location will be made "soon," he adds. "But no definitive date has been set."The network operations center, in Herndon, Va., oversees the entire ADS-B ground infrastructure by monitoring the radios, cabinet temperature -- "generally, to make sure it's all up and running," Kefaliotis says. A backup center exists in an undisclosed location.