有源导前假目标形成的理论与方法研究

Repeater jamming is one of the chief countermeasure against modern radar systems. By receiving, modulating and retransmitting, repeater can come into being vivid false targets in radar system. However, these false targets always appear behind the real ones for the reason of system delay, which lead to it become difficult for repeater counterworking ECCM measures such as leading-edge range tracking, pulse-to-pulse repetition-period staggering, and so on. How to form preceded false targets has become a focus in radar counter. Group Delay theory and Paired-echo theory explain the generation of preceded false targets in some degree, but the diversity of radar signals and signal processing methods vary the reasons for preceded false targets generation, which lack systematic and depth interpretation in theory. Aimming at this problem, this project will study the inner nature of preceded false targets' generation, analyze the dynamic characteristics of preceded false targets, expound the nice characteristics distinction between the real and the false targets, make breakthroughs in one-dimensional wideband active preceded false targets modulation and two-dimensional wideband preceded false targets generation, put forward new jamming measures and application methods to form active preceded false targets, analyze and evaluate the experiments' results. The production of this project will provide theory basis and technical support for novel active jammings' argumentation, designation and application.

转发干扰是现代雷达对抗的主要手段之一，通过复制-调制-转发等技术手段，可形成逼真的假目标。但在自卫干扰中，由于系统延迟等原因，形成的假目标总是滞后于真实目标，难以对抗雷达的前沿跟踪、重频抖动等抗干扰措施。如何实现假目标导前，是当前雷达对抗领域关注的难点之一。 群延迟理论和成对回波理论在一定层面上阐释了假目标导前内在机理，但雷达信号的多样性和处理方法的差异性使得假目标导前的原因各有不同，而这方面缺乏系统深入的理论探索。本项目力图在有源导前假目标形成的理论与方法上有新突破：针对现代雷达系统，研究导前假目标形成的内在机理；分析导前假目标的动态特性，揭示真假目标之间的细微特征差异；突破一维宽带有源宽带有源假目标导前调制、二维宽带有源导前假目标形成等关键技术，提出形成有源导前假目标的新型干扰样式及应用方法，分析评估试验结果，为新型有源干扰的论证、设计及其应用提供理论依据和技术支撑。

本项目研究了有源导前假目标的理论与应用方法，丰富和完善了有源导前假目标干扰理论体系，在成像雷达的欺骗干扰机理及干扰样式上取得了新突破：从理论上解释了导前假目标形成的内在机理，并分析了其空间分布特性；针对宽带成像雷达系统，建立了间歇采样转发干扰的理论框架，分析了宽带相干假目标的分布特性，揭示了基于间歇采样的逆合成孔径雷达的干扰机理；研究了相位调制表面（phase switched screen，简称PSS）对成像雷达目标特征的精确调制技术,详细分析了相位调制表面在线性调频信号照射条件下的调制信号模型和回波信号模型，并研究了PSS回波信号经过成像雷达距离向成像处理和方位向成像处理后的输出特性，提出了基于PSS的高分辨距离像干扰方法和成像雷达二维干扰方法。本研究成果可为新型宽带有源干扰机的论证、设计及其应用提供理论依据和技术支撑。