STEWART PENNEY / EDINBURGH
New technology provides 1m resolution reconnaissance standard pictures from fighter
BAE Systems Avionics has demonstrated 1m-resolution synthetic aperture radar (SAR) images from a mechanically scanned-array fighter radar and is one design iteration away from a production system.
The system uses commercial off-the-shelf, silicon-based processing on the receive side of a radar to improve image resolution (Flight International, 19-25 February, 2002).
BAE Avionics director of technology Professor John Roulston says "we've demonstrated 1m resolution". He adds that the "stretch" system has been offered as part of enhancements to the Eurofighter Typhoon's Captor radar within the Tranche 2 upgrade proposal. He says the system will likely be part of the Tranche 2 package and is attracting strong interest from potential Typhoon export customers. "So it justified the work," he says. BAE self-funded the development.
Over the last year BAE has refined the system and has a prototype mounted on a card that fits into a radar's processing box. It has used the system in flight trials, the most recent last December, using a Captor radar mounted in the company's BAe One-Eleven hack aircraft.
The new card "is production performance; previously we demonstrated 2-2.5m resolution, now we've done 1m", says Roulston.
Roulston says "there is probably one more design iteration" before the system is ready for production. As the "stretch" is embedded in the radar's receive circuits, the system can be added to a radar without changing its volume requirements.
The gallium arsenide microwave circuits are ready, but the cost of the silicon-based elements needs to be cut, by reducing the number of "tiles" and altering the base material, he says.
Roulston says that using a field programmable gate array (FPGA) in place of an application-specific integrated circuit will reduce overall cost. FPGAs, because they are families of components, also mean obsolescence should be less of a problem, he adds.
Source: Flight International
