Multichannel SAR imaging with backprojection

Abstract

The use of multiple antennas on a synthetic aperture radar (SAR), i.e., multichannel SAR, offers benefits such as improved ambiguity suppression for moving target indication (MTI) and imaging large swaths (Goodman, N.A. et al. 2002; Ender, J.H.G., 2000), improved signal-to-noise ratio (SNR) (Younis, M. et al., 2003) and the potential to suppress spatial jammers by use of space time adaptive processing (Ender, 1998). The multichannel matched filter (MF) interpolation imaging scheme presented by L. Rosenberg and D. Gray (see Int. Radar Symp. Proc., 2004) offers a good tradeoff between imaging accuracy and computational complexity. However, there are a number of potential problems which affect this algorithm in practice. Backprojection offers a solution to these problems and instead offers a direct tradeoff between accuracy and computation time. We extend the single channel backprojection algorithm to include multiple transmit and receive antennas. An analysis of the performance of the algorithm with varying levels of accuracy is shown, as well as a comparison with conventional MF algorithms.