GRAHAM WARWICK / WASHINGTON DC
Lockheed Martin team to provide GPS augmentation under $597 million contract
A Lockheed Martin-led team is to provide leased satellite communications services for the US Federal Aviation Administration's GPS wide-area augmentation system (WAAS). The contract, potentially worth $597 million, includes a third geostationary (GEO) satellite payload to be operational by 2006 to increase WAAS availability.
The FAA's local-area augmentation system (LAAS) programme has been restructured to avoid integrity problems that have delayed commissioning of WAAS, originally scheduled for 2000. A LAAS full-scale development contract is expected to be awarded next month.
The FAA hopes to commission WAAS in July, after its acceptance inspection with prime contractor Raytheon in January. At initial operational capability, the system will provide lateral and vertical navigation (LNAV/VNAV) down to a height above threshold of 350ft (107m). Guidance down to 250ft will be provided "soon after", FAAWAAS team leader Hal Bell told the RTCA Symposium in Washington DC late last month.
WAAS signals are broadcast on GPS frequencies via payloads installed on two Inmarsat satellites, one over the Atlantic and one over the Pacific. With two satellites "there is a large risk of losing service," says Bell. The FAA wants the third payload to be on a satellite in the 119°W geostationary orbital slot, from where it can cover the USA, including Alaska. "If we lose 119°W, we lose Alaska. We are trying to find the best satellite [to host the payload]," he says.
Lockheed Martin, with Boeing and Raytheon, will provide ground stations and broadcast services. The contract allows the FAA to procure up to three GEO payloads on 10-year leases. "We can exercise the option to put a transceiver on quickly, to catch a satellite as it comes through the system," says Bell.
Three GEO satellites will increase availability of the LNAV/VNAV service and are required for WAAS full operational capability, now scheduled for 2007. Bell says WAAS can provide precision approach guidance equivalent to Category I, but it requires dual-frequency GPS "so we can do real-time ionospheric corrections in the cockpit". The second GPS civil frequency, L5, will not be available until 2015.
Honeywell, Raytheon and Thales, meanwhile, are competing for the LAAS contract, which includes low-rate initial production of 10 Cat I ground stations and options for 15-40 systems a year over five years. The programme has been restructured to include an integrity demonstration, delaying initial operational capability by a year to September 2006. A decision of full-scale development of Cat 2/3 LAAS is planned for 2005, leading to initial operational capability in September 2008.
Source: Flight International
