Swathbuckler wide area SAR processing front end

The Swathbuckler international collaboration task between government laboratories of US, Canada, UK and Australia has jointly implemented an affordable, experimental, real-time, wide-swath SAR imaging radar system. This paper is one of a coordinated collection of papers submitted by the collaboration partners. It describes the radar processing front-end component of Swathbuckler, responsible for the intelligent interface between SAR radar and the high-performance computing cluster. The unique requirements of this program, namely the real-time processing of SAR swaths encompassing 250,000 range samples, dictated a novel reconfigurable FPGA architecture for this interface. The associated firmware performs high-speed digitization, digital down-conversion and distribution to each of the nodes in the computing cluster. The design has evolved from early attempts to develop a custom prototype through to an integrated solution using commercially available hardware. The interface has successfully flown in Swathbuckler flights supporting wide-swath, high resolution SAR processing at a sustained 500 Hz pulse repetition frequency. The work has demonstrated that it is possible, with currently available and technology, to provide an affordable, compact means of managing unprecedented SAR swath sizes in an airborne platform.