Abstract:

The interrepted sampling repeater jamming (ISRJ) is a form of coherent jamming that poses a significant threat to modern radar systems. In complex scenarios with high jamming time-domain duty cycles (JTDC) ratio or weak energy jamming, ISRJ slices can overlap with the energy close to the real targets, which leads to the traditional time-frequency domain algorithms less effective, even renders them ineffective. In response to this challenge, an ISRJ suppression algorithm optimized for complex scenarios is proposed, starting from the ISRJ time-frequency coupling mechanism. The proposed algorithm follows a "decoupling-filtering-reconstructing" process to handle jamming echoes. Firstly, it initially employs time-frequency decoupling transformation to align multiple repeater slices, effectively reducing the JDTC. Subsequently, it partitions noise regions and binarizes the time-frequency chart by a low threshold principle. Following that, it generates a time-domain mask based on the most conservative principles to eliminate jamming. Finally, it utilizes intermittent CLEAN technology to reconstruct the complete target echoes. Multiple sets of simulation experiments are conducted to validate the effectiveness of the proposed algorithm. It analyzes the impact of change of multiple sets of parameter on performance and assesses the algorithm's real-time capabilities. Theoretical analysis and simulation results collectively confirm that compared to traditional filtering-based anti-ISRJ algorithms, the proposed algorithm exhibits superior jamming suppression performance in complex jamming scenarios, particularly those involving high JDTC ratio and weak energy jamming.

Key words: interrupted sampling repeater jamming (ISRJ), CLEAN technology, time-frequency analysis, dechirping processing