A Fast Transient Interference Suppression Method for OTHR Based on $\ell _{p}$ Norm and Overlapping Block Sparse

Transient interference is a high-frequency signal in skywave over-the-horizon radar (OTHR) that is incoherent with the radar waveform. It significantly increases the noise level in the Doppler domain, thereby degrading detection performance. In this article, a transient interference suppression method is proposed for OTHR based on $\ell _{p}$ norm and overlapping block sparse (LPOBS). First, the properties of the echo signal are analyzed, that is, the sparsity of the slow-time domain transient interference component, the Doppler domain target and sea clutter components, as well as the block sparsity of the sea clutter with a priori-known location in the Doppler domain. Subsequently, an objective function is constructed and a computationally efficient algorithm is proposed to solve the objective function through the alternating direction method of multipliers framework. Unlike the traditional method of “interference localization followed by data recovery,” the LPOBS can separate the transient interference and recover the uncontaminated data without the interference localization. Finally, the semisimulation data and actual data provide experimental evidence that the LPOBS exhibits remarkable superiority in terms of spectrum reconstruction accuracy, output signal-to-noise ratio, and computational efficiency.