Overview: Gravitational waves are spacetime oscillations radiated outward by accelerating mass objects. Significant astronomical events in the universe, such as the merging of massive black holes, emit stronger gravitational waves. Detecting gravitational waves allows for a deeper study of the laws governing celestial bodies and the origins of the universe, making accurate detection crucial. Gravitational wave detection technology utilizes Michelson interferometers to convert the extremely faint spacetime fluctuations caused by gravitational waves into measurable changes in optical path length. Recently, ground-based large Michelson interferometers have achieved direct detection of high-frequency gravitational waves. However, the detection of low-frequency gravitational waves, which is equally important, is not feasible on the ground due to arm length and ground noise issues. This necessitates the construction of ultra-large Michelson interferometers in space for low-frequency gravitational wave detection. Spaceborne gravitational wave detection telescopes play a vital role in collimating bidirectional beams in ultra-long interferometric optical paths in space. The extremely subtle changes in optical path caused by gravitational waves impose high demands for pm-level optical path length stability and below 10^?10 level backscattered light in these telescopes. The ultra-high level index requirements exceed the precision limits of current ground testing techniques for telescopes. To ensure that spaceborne telescopes maintain their ultra-high design performance in the orbital environment, developing testing and evaluation techniques for these key indicators is a crucial prerequisite for the success of the space gravitational wave detection program. This paper provides an overview of the development of spaceborne gravitational wave detection telescopes, both domestically and internationally. It focuses on the current status and some test results of optical path length stability and backscattered light testing of telescopes under development, as well as further testing plans, providing a reference for the testing and evaluation of Chinese space gravitational wave detection space-borne telescopes.

为实现包装盒纸质基底层和透明膜层缺陷的同步检测，开展了对纸和膜缺陷的同步成像研究。首先，分别建立了标准球面积分光场、椭球面积分光场和弧面积分光场模型，并利用COMSOL Multiphysics 5.6对3类光场进行射线仿真，对比分析了球面积分光场下射线角度均匀性及辐照均匀性，通过正交仿真优化椭球面积分光场参数；其次，在椭球面积分光场环境、亮场前打光环境、暗场前打光环境下对包装盒成像。与此同时，对包装盒的油污、抵触、开口、泡皱、破损5项常见缺陷依次进行物理检测和机器视觉检测，验证缺陷成像的有效性。试验结果表明，在椭球面积分光场下成像，图像对纸质基底层缺陷特征、透明膜层缺陷特征均有较好的呈现效果，图像上油污、抵触、开口、泡皱、破损的物理检出率分别为96.2%、92.5%、100%、95%、92%，异常检出率分别为98.6%、97.5%、100%、100%、98.4%，缺陷类别检出率分别为97.6%、96%、100%、97%、96%。研究结果表明，椭球面积分光场光路角度和辐照强度均匀，覆透明膜包装盒的缺陷特征呈现清晰，满足工业生产的检测要求。

针对光路对接准直目标识别算法对双目标粘连状态无法判别的问题，提出了基于二进制大对象（Binary Large Object，BLOB）区域和边缘特征分析的准直图像双光学目标识别方法。首先，对二值化图像进行数字形态学处理，计算全图各BLOB区域的面积、中心、轴长、区域、有效BLOB区域个数等信息。其次，对有效BLOB区域个数大于1的完全分离双目标准直图像，统计各BLOB区域中心分别为位于两个面积最大的BLOB区域内的BLOB数量，数量小的候选BLOB区域为主激光目标，数量大的候选BLOB区域为模拟光目标。然后，对于有效BLOB区域个数等于1的待识别图像，从左、右、上、下4个方向分别提取模板边缘图像的有效坐标序列和待识别边缘图像坐标序列，搜索有效坐标序列和待识别边缘图像坐标序列的最大相关系数对应的有效坐标序列。当4个方向的相关系数全部大于0.95时，待识别图像为模拟光目标；当4个方向的相关系数都小于0.95时，待识别图像为主激光目标；否则待识别图像为粘连图像。实验结果表明：提出的双光学目标识别算法，不仅能够识别完全分离的模拟光目标和主激光目标，误差小于3个像素，处理时间小于1 s，而且能够判别处于粘连状态的光学目标和单个独立的光学目标，满足光路对接准直图像识别算法对于自适应性、精度和效率的要求。

回顾了国外军队装备的四代光电瞄准吊舱的技术特点和发展历程，定义了光学口径和吊舱舱径之比（光舱比）作为衡量集成度的标准，重点针对第三代的Sniper XR ATP和ATFLIR两型采用共光路串联布局吊舱的探测系统进行了分析和正向设计：二者均拥有Φ150 mm口径，约1.5°×1.5°视场，在0.7~0.9 μm和3.7~4.8 μm波段的传递函数接近衍射限，前者为透射式前置望远系统，后者为离轴三反式前置望远系统，二者的结构布局为：前置望远系统置于吊舱前部压缩光束，通过光学铰链和快反镜将光束导入吊舱中，部分光进入各自的探测通道或激光发射通道。其中，类ATP的透射式前置望远系统可在汇聚光路中折叠形成俯仰/方位正交轴系并置于305 mm舱径内，光舱比约0.492；类ATFLIR的离轴三反式前置望远系统可在压缩后的平行光路中折叠形成方位/俯仰两个正交轴系并置于Φ330 mm的球体内，光舱比约0.455。作为对比，采用共光舱并联布局的第四代Litening 5和Talios吊舱探测系统将所有光学载荷和伺服框架平台置于吊舱前部的Φ406 mm球体内，光舱比约0.37，其并联共光舱设计架构的集成度较低。针对未来可能的升级要求，类ATFLIR吊舱比ATP吊舱具有更强的生命力，其采用纯反射式的前置望远系统可以更方便地增加波段和拓展功能。