空间激光主动探测离轴三反系统的猫眼效应

采用光线追迹法,分析了空间环境下离轴三反结构系统的猫眼效应。给出了离轴三反系统的像面倾斜、视场和离焦对猫眼回波效率和发散角的影响,证明了离轴三反系统像面倾斜量是决定能否发生猫眼效应的主要因素。提出利用阈值法实现激光主动探测猫眼信号的基本原理,并结合高阶余弦漫反射模型,分析了目标漫反射信号对猫眼信号检测的影响。估算了20km到120km探测距离下,理论上所需不同光束质量激光的最小脉冲能量。仿真表明,当发射光束的全角发散角为0.3mrad时,50km和120km探测距离下所需的最小激光脉冲能量分别为0.7mJ和3.1mJ。最后,通过原理实验,验证了空间激光主动探测法探测目标"猫眼"效应的可行性。

Active laser detection of cat's eye effect for space-based off-axis three mirror optical system

The cat's eye effect of a space-based Off-axis Three Mirror (OTM) system was analyzed by using the ray tracing method. The effects of image tilt, views of field and the defocus of the OTM system on the echo efficiency and beam divergence angle of cat's eye retro-reflection were given. Then, it pointed out that the image tilt size of the OTM system is a main factor to produce cat's eye echo wave. A threshold method was proposed to actively detect the cat's eye signals, then the influence of diffuse reflection from a target on the detection of cat's eye signals was analyzed by combining the high order cosine scattering mode. The minimum laser pulse energy requirements for 20 km to 120 km detection range under different transmissive beam qualities were given theoretically. The simulation results show that when the beam divergence entire angle is 0.3 mrad, the minimum laser pulse energy requirements at the detection distances of 50 km and 120 km are 0.7 mJ and 3.1 mJ, respectively. Finally, an experiment was carried out to verify the feasibility of the active detection of OTM systems with the cat's eye effects.