基于干涉的猫眼效应反射光空间分布时间化机理与方法

Most military optical targets such as sighting telescopes, night vision goggles and range finders, can be detected and localized effectively by active laser detection system based on cat eye effect. The active laser technique plays a greatly important role in antiterrorism and modern high-tech war. However, a dominating technical problem exists in the incorrect identification of the target, which is caused by the reflections of complex background, glasses, journalists' camera lens and so on. To solve this urgent technical problem on optical target recognition, time transformation mechanism and methods on space distribution of cat-eye effect reflected light basing on interference are developed. By dynamic cat-eye effect transformation model and laser interference methods, the space distribution signals which include plenty of target information but difficult to be measured under farfield distance, can be changed into measurable time distribution signals. The emphasis is mainly put on the modulation process of laser beams passing through dynamic cat-eye effect model and the mechanism of space distributions transforming into time distributions. Acquisition methods of time distribution will be found by launching active interference laser beams or using the interference between incident beam and reflected beam. What's more, theoretical simulations and validation experiments are done to constitute the mapping relationships between target features and time-frequency characteristics including frequency spectrum, fluctuation variance, and probability distribution. This research could further improve the stray light filtering capability of the active laser detection system, and make it possible to recognize the target style and some parameters including vibration spectrum, optical aperture, and so on.

基于猫眼效应的激光主动探测系统可实现对瞄准镜、夜视镜和测距机等军用光学目标的有效探测和快速定位，在反恐维和与现代战争中发挥着突出作用。但复杂背景、玻璃表面和记者相机等非威慑目标造成的探测系统误判是目前的突出问题。针对此迫切需要解决的光学目标识别技术难题，本项目提出开展基于干涉的猫眼效应反射光空间分布时间化机理与方法研究。拟通过建立动态猫眼效应变换模型和激光干涉方法，将包含有目标信息特征但却无法远距离测量的反射光空间分布，转化为可测量的时间分布。重点研究激光束通过动态猫眼效应模型的调制过程和空间时间变换机理，建立主动发射干涉激光束以及入射光反射光相干涉这两种条件下的反射光时间分布获取方法，并通过数值仿真与验证实验建立目标类型及参数与回波频谱、起伏方差、概率分布等时频特征的映射关系。该方法可提高激光主动探测系统的杂光抑制能力，并使之具备对目标类型和振动频率、光学口径等参数的识别能力。

基于猫眼效应的激光主动探测系统可实现对瞄准镜、夜视镜和测距机等军用光学目标的有效探测和快速定位，在反恐维和与现代战争中发挥着突出作用。但复杂背景、玻璃表面和记者相机等非威慑目标造成的探测系统误判是目前的突出问题。. 针对此迫切需要解决的光学目标识别技术难题，本项目提出开展基于干涉的猫眼效应反射光空间分布时间化机理与方法研究。重点研究了激光束通过动态猫眼效应模型的调制过程和空间时间变换机理，建立了包含目标位置姿态、大气环境等因素的猫眼效应动态模型，并推导了猫眼效应反射光束畸变参数的解析表达式，分析了可变量对反射光空间分布时间变化的影响规律，为激光主动探测系统定量分析和反射光时间分布获取方法的建立奠定了基础。. 建立了基于激光主动干涉的反射光时间分布获取方法，分析了空间干涉场经不同目标反射后的时间化过程和规律，并通过理论和实验分析了干涉光束扫描不同目标时的反射光时间分布受干涉条纹间距、目标光学口径等因素的影响规律，并从理论上分析大气传输对反射光相干性的影响，结果表明该方法可以利用光学目标和漫反射目标对干涉光束反射光时间序列信号特征的差异，将光学目标从复杂漫反射背景中快速识别出来，并可估计出镜头类目标的口径，进一步缩小识别范围。 . 建立了基于反射光入射光干涉的反射光时间分布获取方法，通过理论和实验，分析了目标动作对接收干涉光强分布的时间调制规律，结果表明该方法可以从漫反射背景中识别出光学目标的存在，并可识别出目标的振动频率等。. 组建了两套实验系统，验证了激光主动干涉识别方法和入射光发射光干涉识别方法用于光学目标探测与识别领域的可行性和适用性，虽然实验距离只有为100m和20m，但推算可知其适用探测距离可达500m和100m，理论作用距离更高。