Multi-mode clutter suppression of MIMO-OTH radar using blind source separation

Spread-Doppler clutter (SDC) caused by multi-mode propagation seriously affects the over-the-horizon radar (OTHR) detection performance for slow ships. To solve this problem, we propose to suppress multi-mode SDC using spatial information in the multiple-input multiple-output over-the-horizon (MIMO-OTH) radar system. Traditional processing algorithms need priori information of the target direction, which is often not readily available. In this paper, we propose a novel multi-mode clutter suppression algorithm based on the second-order blind identification (SOBI) technology. The proposed algorithm does not need prior information of the target direction and can effectively suppress the multi-mode clutter. Simulation results show that the method not only achieves better suppression of the multi-mode SDC, but also retains the clutter information which contains a lot of useful information in many cases.