Transient Interference Suppression Based on Minimax Concave Penalty for OTHR

Detection performance of the over-the-horizon radar (OTHR) is seriously affected by transient interference such as atmospheric noise, meteor echoes, and lightning strikes. In this letter, a transient interference suppression method is proposed based on minimax concave (MC) penalty. The proposed method utilizes the sparsity of transient interference in the time domain and sea clutter (or targets) in the frequency domain. The sparsity is constrained by MC penalty in the objective function, and an $\ell _{2} $ -norm is applied to separate noise components. Finally, the extended projected generalized gradient (PGG) method is used to minimize the objective function to suppress transient interference. Without additional interference localization and data completion, the proposed method locates, suppresses the transient interference, and recovers pure spectrum simultaneously. In addition, it has higher spectrum reconstruction accuracy and output signal-to-noise ratio (SNR) compared with the existing methods. The effectiveness of the proposed method is verified by the real data of the OTHR.