Ionospheric clutter analysis and suppression in a distributed MIMO-HFSWR system

In distributed MIMO (multiple-input-multiple-output)-HFSWR (high frequency surface wave radar), multiple detection modes are introduced to enrich the detection information, however making ionospheric clutter more complicated. In this paper, a distributed MIMO-HFSWR system involving three monostatic radars is introduced. Sea echo and ionospheric clutters from different paths are received simultaneously by MIMO system. Characteristic of ionospheric clutter in range domain and Doppler domain are analyzed with measured data. It is discovered that the correlation of ionospheric clutters from different paths is higher than of sea echoes. Based on this, a novel method for clutter suppression is proposed via adaptive filter using clutters from different paths as secondary data. Experimental results show that the analysis and processing method are feasible and effective.