Moving target indication with dual frequency millimeter wave SAR

Ground moving target indication (GMTI) for synthetic aperture radar (SAR) provides information on non-static objects in a static ground scene. An efficient approach for GMTI is the use of multi-channel SAR systems for a space- and time-variant analysis of moving targets. This allows the indication, correction of position errors, and estimation of radial velocity components for moving targets in the SAR image. All three steps are possible because of the Doppler frequency shift in the radar signal caused by the radial target movement. Our work focuses on the millimeter wave (mmW) SAR system MEMPHIS with multi-channel amplitude-comparison monopulse data recording and the ability to use carrier frequencies of 35 and 94 GHz simultaneously, making it a dual frequency multi-channel SAR. Our discussions include mmW specific SAR GMTI considerations and an adaptive algorithm to collect information on moving targets with a mmW monopulse radar, and GMTI blind speed elimination and target velocity ambiguity resolving by dual frequency SAR. For an experiment with MEMPHIS, frequency spectra, processed SAR images with position corrected moving targets, and accurate target velocities and positions are presented to verify the developed algorithm.