Ionospheric clutter mitigation with knowledge aided pre-whiten in High Frequency Surface Wave Radar

Ionospheric clutter has proven to be the greatest impediment in high frequency surface wave radar (HFSWR). It influences most range bins, all Doppler bins and beams. Knowledge-aided ionospheric clutter mitigation using multiple coherent processing interval (CPI) data was described. The approach is based on estimation of the near vertical incidence clutter by past CPI data to provide improved knowledge of clutter statistics. Knowledge aided pre-whitening filter was used to cancel both near vertical incidence clutter and the range wrap clutter. Experimental results demonstrate that the algorithm is able to suppress the ionospheric clutter whilst preserving the desired characteristics of the target echoes.