RAMON LOPEZ / BEALE AFB, CALIFORNIA
Technical problems which beset the synthetic aperture sensor have been overcome
The US Air Force's 9th Reconnaissance Wing (9RW) received its first Raytheon ASARS-2A synthetic aperture radar on 30 August, 24 months later than expected due to technical problems.
The ASARS-2A, also known as the ASARS-2 Improvement Programme (AIP), is an upgrade of the high-resolution reconnaissance system equipping the Lockheed Martin U-2 high-altitude reconnaissance aircraft. It produces radar images in all weathers, day or night and has a ground moving target indication (GMTI) capability.
AIP improvements are based on commercial off-the-shelf (COTS) technology and include: real-time, precision targeting; broad area synoptic coverage; on-board processing for a four-fold increase in search coverage; a spot mode that is nine times larger than that currently fielded; and enhanced GMTI. The production system has a new on-board processor (OBP) and receiver/exciter/controller, a re-packaged low voltage power supply, and legacy ASARS-2 antenna and transmitter components.
Flight testing began in June 1999and Raytheon planned to deliver the first ASARS-2A early last year, but completion of the AIP development supporting ASARS-2A production has suffered a two-year delay, says Lt Col Patrick Fillingim, U-2 developments systems manager.
"Several COTS components selected for this development did not meet the expected performance, and resultant mitigation efforts impacted Raytheon's development schedule," he says.
Some COTS items were unable to operate at extreme temperatures. Fillingim says: "Modifications to the OBP chassis are under way to ensure that the ASARS-2A can operate throughout the temperature range the U-2 experiences worldwide." Modifications are "not technically challenging" and will be completed shortly.
He says, however, that variations in COTS components remain a challenge to system development and production. These variations have contributed to ASARS-2A robustness problems. Follow-on development and sustainment efforts are in place to improve the maturity and availability of the ASARS-2A system.
Development flights have provided sufficient confidence in system performance to support its installation, with a force deployment evaluation to be conducted before the end of this year, he says.
Raytheon's ASARS-2A award is valued at $96 million. The number of units to be delivered is classified, but Fillingim says: "The USAF is procuring sufficient ASARS-2A systems to support U-2 operating locations worldwide." The USAF has 31 General Electric F118-101-powered U-2Ss and four U-2ST trainers.
Source: Flight International