Ionospheric clutter reduction for high-frequency surface-wave radar based on time-frequency-ridgelet filtering

The existence of ionosphere clutter, the target limits the performance of high frequency surface wave radar (HFSWR). It is more desirable to solve the problem of ionosphere clutter mitigation. Existing methods suffer difficulty when the clutter is nonstationary. To overcome this issue, a novel ionospheric clutter mitigation algorithm based on Time-Frequency-Ridgelet Filtering (TFRF) is proposed in this paper. Our study shows that the time-frequency ridgelet coefficients of the clutter are nonstationary, whereas the targets' are stationary. Therefore, the ionosphere clutter can be reduced by the TFRF method. Experimental results show that the proposed TFRF method can effectively mitigate the nonstationary ionospheric clutter, and can improve the Signal to Clutter and Noise Ratio and the detection performance of HFSWR.