SAR-Like Multi-Input Multi-Output Radar for Naval Applications

Coherent Multi-Input Multi-Output (MIMO) radars enable angular resolution in fixed-antennas radar systems. To reduce the angular ambiguity given by the sidelobes, it is necessary to increase the spatial information using several distributed antennas. However, this increases considerably the system complexity and cost. In this paper, we present a novel processing scheme that combines the principle of Synthetic Aperture Radar (SAR) to a MIMO system with widely separated antennas. Exploiting multiple consecutive observations, the spatial information increases and the sidelobes are considerably mitigated. The approach is particularly suitable for naval scenarios, where the low speed of the platform and the long pulse repetition interval make the MIMO processing more indicated than SAR. A simulative analysis considering realistic parameters for a maritime application reveal a sidelobe suppression enhancement as high as 14 dB. Moreover, specific tests show that an error of 10% in the estimation of the platform speed does not affect the overall detection performance. The proposed approach appears very promising since the SAR-like data fusion allows lowering the sidelobes while preserving the high cross-range resolution enabled by the coherent MIMO processing.