Cascaded method for ionospheric decontamination and sea clutter suppression for high-frequency hybrid sky-surface wave radar

In high-frequency (HF) hybrid sky-surface wave radar, the first-order sea clutter broadening is very severely under the influence of ionosphere and bistatic angle, which affects the detection of ship target. In this study, a cascaded method for ionospheric decontamination and sea clutter suppression to enable detection of ship target is presented. Firstly, the radar configuration, sea clutter broadening characteristics, and model are introduced based on the newly-developed integrated HF sky-surface wave experimental system. In the cascaded processing method, the time-frequency analysis method based on S²-method is used to correct the ionospheric phase contamination with large amplitude. Then, a novel forward-backward linear prediction algorithm is proposed to suppress the broadening bistatic sea clutter caused by bistatic angle, which is based on the distribution characteristics and the multi-dimensional feature of first-order sea clutter. Finally, the proposed method is examined by measured data. Experimental results indicate that the proposed method can well suppress the broadening sea clutter and improve the ship target detection performance.