有源欺骗干扰是针对逆合成孔径雷达(ISAR)的一种较成熟的干扰技术,但抗欺骗干扰技术研究尚有欠缺。文中在分析欺骗干扰信号生成原理的基础上,采用脉间调频率微调的方法,使得虚假目标信号与雷达解线频调脉压参考信号的调频率失配,以降低虚假目标的脉压增益。但由于调频率脉间随机变化,会造成成像积累时间内不同调频率回波信号无法相参积累,难以进行方位向高分辨成像的问题。为解决这个问题,提出了采用压缩感知技术,对调频率相同的稀疏回波进行信号重构,以获取真实目标的ISAR 图像。此外,利用干扰信号调频率失配时的距离像特性,文中还提出基于距离像熵值的智能化干扰感知方法,能够准确判断雷达是否遭受干扰,为雷达决策采用抗干扰工作模式提供依据。仿真结果表明所提方法可以准确感知干扰,能够在有源欺骗干扰情况下抑制假目标回波,得到真实目标清晰的ISAR 像。

Active deception jamming technology against inverse synthetic aperture radar (ISAR) is relatively mature, but research on anti deception jamming technology is still deficient. Through the analysis of the generation of false targets jamming signals, a method is used to reduce the echo gain of false targets by varying the chirp rates between pulses, which can make the chirp rate mismatch between the false target signal and the dechirp reference signal. However, due to the random variation of chirp rates, it is difficult to perform azimuth high-resolution imaging because echo signals with different chirp rates cannot be coherently accumulated during the imaging accumulation time. To address this issue, compressive sensing technology is performed on sparse echoes with the same chirp rate for signal reconstruction and ISAR imaging. In addition, based on the characteristics of the range profile when the chirp rate of the jamming signal is mismatched, an intelligent jamming perception method based on the entropy of the range profile is proposed, which can accurately determine whether the radar is affected by jamming and provide a basis for radar decision-making to adopt anti-jamming working mode. Simulation results show that the proposed method can accurately perceive jamming, suppress false target echoes under active deception jamming, and obtain clear ISAR images of the real target.

TN974

南京工业职业技术大学科研启动基金资助项目