Transient Interference Suppression Algorithm Based on Time Frequency Sparse Prior for Skywave OTHR

The target detection performance of skywave Over-the-Horizon Radar (OTHR) often struggles with transient interference. To address this issue, we have developed a transient interference suppression algorithm that uses Time Frequency Sparsity Prior (TFSP). TFSP uses the sparse nature of transient interference in the slow-time domain along with the sparse prior of sea clutter and targets in the Doppler frequency domain to construct an objective function, that is optimized using the Alternating Direction Method of Multipliers (ADMM) to effectively suppress transient interference. Unlike traditional methods that focus on locating and eliminating interference before recovering data, TFSP can directly separate transient interference components and restore an interference-free Doppler spectrum. Experimental results from OTHR data confirm that TFSP effectively suppresses transient interference in sea and air modes. TFSP offers a higher output Signal-to-Noise Ratio (SNR) and higher computational efficiency than most existing methods. In particular, it increases the output SNR by approximately 3～5 dB while maintaining computational complexity at a linear logarithmic order.