Real-time implementation of UWB-OFDM synthetic aperture radar imaging

Abstract

Real-time implementation of high resolution and jamming-resistant ultra-wideband, orthogonal frequency division multiplexing (UWB-OFDM) synthetic aperture radar (SAR) imaging system is presented based on the use of field programmable gate array (FPGA). Range-doppler algorithm (RDA) is used to reconstruct high resolution SAR image from raw data. Suitable waveforms to achieve high resolution SAR imaging are proposed for both friendly and hostile environments. The proposed waveforms were tested for full two dimensional SAR image construction. The huge computation task of SAR imaging concentrates on range and azimuth compression which in turns heavily depends on computing FFT/IFFT and complex multiplications as part of the RDA algorithm. To achieve realtime SAR image reconstruction, an FPGA model is designed using 'shared memory' approach provided with Xilinx block-set. The model is implemented as hardware co-simulation using system generator on Xilinx Virtex-6 ML605 FPGA board.