Optimal Filtering for MIMO SAR: Mismatched Filters for Minimum Integrated Sidelobe Ratio

Abstract:
By simultaneously transmitting multiple waveforms, a multiple-input, multiple-output (MIMO) synthetic aperture radar (SAR) retains transmit degrees of freedom, which can be used to enhance area-coverage rate. This comes at the cost of degraded range-sidelobe performance from the cross-correlation between waveforms. The corresponding degradation in contrast will severely limit the utility of MIMO SAR imagery. This paper presents a new approach for designing optimal filters that minimize the integrated sidelobe ratio (ISR) for MIMO radar. Unlike other approaches presented in the literature, this new method jointly applies pulse compression and spatial beamforming, which allows improved sidelobe control compared to techniques that apply these processing stages in a separable manner.