By John Rhea
GOODYEAR, Ariz. - Scientists at Lockheed Martin Tactical Defense Systems in Goodyear, Ariz., have demonstrated a UHF synthetic aperture radar (SAR) capable of finding targets in dense foliage in real time by developing target detection algorithms to run on standard, high-powered commercial computers.
SARs normally operate at X-band frequencies, which cannot readily distinguish targets under tree canopies.
The demonstration, sponsored by the U.S. Defense Advanced Research Projects Agency in Arlington, Va., and the U.S. Air Force`s Wright Laboratory in Dayton, Ohio, used a UHF radar installed in a U.S. Navy P-3 turboprop aircraft.
The tests were in forested areas around Grayling, Mich., Presque Isle, Maine, and Camp Roberts, Calif. The targets were tanks, armored personnel carriers, and mobile missile launchers.
The tests used the Omega-K large image formation processing algorithm followed by an automatic target detection/cueing (ATD/C) algorithm, which requires high throughput, says Greg Moore, program manager at Lockheed Martin.
The computer, with the necessary 20 gigaflops of throughput, came from Mercury Computer Systems in Chelmsford, Mass. Lockheed Martin engineers have been developing the ATD/C algorithm for several years, and this was the first demonstration of real-time automatic detection of targets under foliage.
The ultimate goal is to mount a UHF SAR radar and a real-time signal processor on an unmanned aerial vehicle such as the Tier 2 plus Global Hawk to find hostile forces in forests. Wright Laboratory has a 3-year program called Radar Detection of Concealed Time-Critical Targets, and Lockheed Martin`s part of the program amounted to a $6.5 million, 36-month effort. The company is due to deliver a complete hardware and software package, including the algorithms and computer, in April 1998.
The significance of Mercury`s RACE computer is that SAR processing frequently required expensive special-purpose processors and this project represented the use of commercial, real-time embedded systems, notes Paul Travers, Lockheed Martin`s director of business development.
The 100 gigaflops in the Mercury line are also necessary for signal intelligence and sonar. But Travers emphasizes foliage penetration radar as an emerging market for this kind of processing.
