Simultaneous High-Resolution Wide-Swath SAR Imaging and Ground Moving Target Indication: Processing Approaches and System Concepts

In this paper, a novel method for enabling ground moving target capability for high-resolution wide-swath (HRWS) synthetic aperture radar (SAR) systems is presented. Such HRWS SAR systems are generally operated with very low pulse repetition frequencies (PRFs). With the novel method, moving target signals highly aliased in Doppler can be reconstructed and the targets´ motion parameters and actual positions can be estimated with high accuracy. A special matched reconstruction filter bank (MRFB) is introduced and incorporated into two novel low PRF ground moving target indication (GMTI) algorithms. Owing to the application of the MRFB, GMTI and HRWS SAR imaging can be performed simultaneously without the need of a separate high PRF system operation mode, which, so far, was necessary for achieving a reasonable GMTI performance. With the MRFB, the advantages of the HRWS imaging principle, i.e., the wide swath and the high resolution are preserved for both HRWS SAR imaging and GMTI. Potential applications are wide-area land and maritime traffic monitoring, where the benefit of the preserved high resolution could, for instance, be used for generating high-quality inverse SAR (ISAR) images for target recognition purposes.