Multiple-Beam IRCI-Free MIMO SAR

A frequency domain system identification based multiple-input multiple-output (FDSI-MIMO) SAR algorithm using multiple phase centre multiple azimuth beam is proposed to obtain high resolution wide swath imaging (HRWS). In this paper, a frequency division multiple access (FDMA) is used in such a way that each transmitter emits a conventional linear frequency modulated (LFM) waveform modulated by a different carrier frequency and the obtained range resolution corresponds to the total transmitted bandwidth. The estimated range profile has ideally zero sidelobes which is the property of free inter-range cell interference (IRCI) although the transmitted waveforms are partially correlated. In addition, a low PRF which is less than the Doppler bandwidth is used to obtain wide swath but without aliasing in the Doppler spectrum.