Robust Wideband Waveforms for Synthetic Aperture Radar (SAR) and Ground Moving Target Indication (GMTI) Applications

The DoD is developing a number of radars to detect and track surface targets including vehicles and dismounts as well image targets using synthetic aperture radar modes. These system achieves wide-area surveillance for dismounts by operating on stationary platforms (helicopter) which eliminates mainbeam clutter spread and allows slow-moving targets to be effectively separated from strong ground clutter based on Doppler shift. Also, the GMTI modes currently employ relatively narrowband waveforms to minimize the impact of target range walk during a coherent processing interval. The SAR mode, on the other hand, employs a much wider bandwidth and requires a moving platform in order to form the synthetic aperture required for image formation. Thus the GMTI and SAR modes represent seemingly conflicting requirements. Namely, traditional GMTI modes work best with stationary platforms and narrow bandwidths, whereas SAR requires a moving platform and wide bandwidth. The proposal describes an approach to develop innovative wideband waveform concepts for simultaneous high resolution SAR and GMTI operation.