Robust ionospheric clutter mitigation method for high frequency surface wave radar

This paper analyzes the characteristics of ionospheric clutter, which has proven to be the greatest impediment in high frequency surface wave radar (HFSWR). Iono-spheric clutter influences most range bins, all Doppler bins and beams, and exhib-its a high directivity. A robust adaptive side-lobe cancellation algorithm based on orthogonal auxiliary beams, which use the difference beams to estimate the iono-spheric clutter information, is introduced to suppress the ionospheric clutter. Training data was selected by excluding the sea clutter and probable target unit; and diagonal loading was added to enhance the robustness of the algorithm. Ex-perimental results demonstrate that the algorithm is able to suppress the iono-spheric clutter whilst preserving the desired characteristics of the target echoes and is suitable for practical implementation.