Multichannel Coprime SAR/GMTI (CopGMTI)

CopSAR and OrthoCopSAR have been recently proposed in the literature to reduce the amount of data to be stored and processed and to extend the maximum swath width that can be imaged without introducing any degradation to the azimuth resolution. Such a High-Resolution Wide-Swath (HRWS) imaging capability is achieved by sampling the synthetic aperture using multiple interlaced sub-Nyquist PRFs. However, a limitation in such imaging modalities is in the assumption that the scene contains only stationary targets. Consequently, moving targets will appear shifted from their true location mostly in the azimuth direction. In this paper, CopGMTI is proposed to detect ground moving targets and estimate their radial velocities when the synthetic aperture is sampled at a sub-Nyquist rate according to CopSAR or OrthoCopSAR. This allows identifying the true azimuth location of such moving targets. Theoretical results provided in this paper are validated using the publicly available Air Force Research Laboratories (AFRL) multichannel SAR GMTI Gotcha data set.