天基数字成像链路数理模型构建方法  

The construction method of space-based digital imaging link mathematical model

作　　者：李亚茹 周亮[1] 刘朝晖[1] 折文集[1] Li Yaru;Zhou Liang;Liu Zhaohui;She Wenji(Xi’an Institute of Optics and Precision Mechanics,Chinese Academy of Sciences,Xi'an 710119,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院西安光学精密机械研究所,陕西西安710119 [2]中国科学院大学,北京100049

出　　处：《红外与激光工程》2023年第12期209-220,共12页Infrared and Laser Engineering

基　　金：国家自然科学基金项目(61805275)。

摘　　要：针对数字化装备构建需求,以天基数字成像系统为研究对象,提出成像链路数理模型构建方法。建立相机、目标光学观测可见性模型和目标几何与光学特性模型,并通过路径追踪全局光照算法及光线重要性采样方法构建成像辐射传输模型,经过光电能量转换及成像调制模型输出空间目标数字成像结果。基于成像平台和空间目标的轨道参数,对比Satellite tool kit(STK)二体轨道模型15 d内的可见性仿真结果,验证了提出的可见性模型的正确性。在时间间隔3 s,距离70~200 km的条件下,对姿态对地定向目标进行成像仿真,结果表明,该成像链路数理模型可以有效生成在满足轨道监测条件下的目标序列图像,同时文中模型对天基装备数字系统建设也具有一定参考价值。Objective With the proposal of digital equipment construction,it is imperative to build space-based digital equipment that can simulate situational awareness capabilities.As one of the core equipment for space-based situational information acquisition,the optical imaging system is inevitably an integral part of the construction of space-based digital equipment systems.Establishing a scientifically and reasonably accurate model of space target imaging link is crucial for constructing a space-based digital imaging system.Additionally,due to the involvement of various scientific and technological fields,the construction of a space target imaging system is characterized by a large-scale system and a long development cycle.Traditional research methods are unable to meet the needs of key technology verification for space-based systems.Therefore,it is also necessary to construct this digital model.By using simulation and comprehensive integration,critical technologies of imaging systems can be validated.Additionally,it provides a demonstration environment for research on space target imaging technology and serves as an auxiliary tool for the design of space-based observation platforms.Methods Based on Kepler's three laws and visibility analysis(Tab.2),this paper constructs a visible model for camera and target optical observations.Based on the uniform smoothing algorithm and advanced wavefront algorithm,the triangulated mesh division technique and the five-parameter bidirectional reflectance distribution function(BRDF)(Tab.3)are used to construct the geometric and optical characteristic model of the target.By employing path tracing and importance sampling of light rays,a global illumination algorithm(Fig.5)is used to construct the imaging radiative transfer model.Finally,the target radiance image undergoes optical-electric energy conversion and imaging modulation(Fig.7)to become the final output image of the sensor.This paper simulates target images satisfying visibility conditions using the Hubble Space Telescope as th

关 键 词：天基成像 数理模型 全局光照 空间目标 

分 类 号：TP391.9[自动化与计算机技术—计算机应用技术]