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.

Overview: Since the groundbreaking discovery of gravitational waves, the scientific community has fervently pursued the exploration of low-frequency gravitational waves to glean deeper insights into the cosmos. The inherent limitations of ground-based conditions, however, pose formidable challenges for detectors in capturing gravitational waves below the 1 Hz threshold. Consequently, the imperative has shifted toward the deployment of space-based gravitational wave detectors as the paramount solution for effective low-frequency gravitational wave detection. At the crux of space-based gravitational wave detection lies the pivotal role of spaceborne telescopes. Given the expansive transmission distances spanning magnitudes of 10⁹ m between celestial constellations, the demand for nanoradian-level precision in telescope pointing accuracy becomes non-negotiable. The concomitant necessity for high-precision measurements and calibration emerges as a prerequisite for achieving the exacting standards of pointing accuracy in spaceborne telescopes dedicated to gravitational wave detection. To ameliorate the deleterious effects of pointing deviations on gravitational wave detection, this study strategically optimizes key parameters, including microlens structures, detector selection, and algorithmic frameworks, thereby achieving a breakthrough in high-precision pointing deviation measurements. Leveraging a low-density microlens array with extended sub-aperture focal lengths enhances the spatial scale of the light spot within each sub-aperture. This, coupled with detectors boasting a high signal-to-noise ratio, synergistically elevates the pointing detection accuracy of each discrete lens. Moreover, the paper introduces an innovative, Hartmann principle-based methodology for high-precision pointing deviation measurements, deploying a spatially reused paradigm across multiple sub-apertures. By aggregating measurement results from diverse sub-apertures, the approach effectively mitigates the influence of assorted random errors on measurement accuracy, thereby markedly enhancing the precision of pointing deviation measurements. Illustrating the efficacy of these methodologies, the paper exemplifies their application within the ambit of the "Tianqin Plan" for space-based gravitational wave detection. Employing numerical simulations and factoring in the design parameters of the Hartmann sensor, the study performs a meticulous analysis of pointing deviation measurement accuracy. Comparative analysis between single sub-aperture and sub-aperture correlation reuse technologies reveals a compelling enhancement in measurement accuracy, approximating a sevenfold improvement with the latter. The pointing deviation measurement accuracy achieved through sub-aperture correlation reuse technology is quantified at approximately 18.81 nanoradians. Considering the optical magnification inherent in spaceborne telescopes, estimated at around 30 times, the resultant pointing deviation measurement accuracy reaches an impressive 0.62 nanoradians. This design precision significantly surpasses the stipulated 1 nanoradian accuracy requirement for ground-based gravitational wave pointing deviation measurements. As a prudential measure, the proposed design incorporates a substantial margin to accommodate potential accuracy diminution attributable to external perturbations during empirical testing.

The empirical findings from this study confirm the superiority of reinforcement learning in formulating effective stray light suppression measures for space gravitational wave detection telescope systems. The approach not only achieves superior suppression outcomes but also introduces an efficient, flexible, and innovative solution to the challenges of stray light in space gravitational wave detection and other high-precision optical systems.

供配电系统是星载偏振成像仪电子学系统的重要组成部分，它不仅要满足将卫星平台提供的一次电源转换成载荷所需的各种二次电源的功能需求，同时还需要满足载荷在轨运行时的高可靠性和长寿命要求。电子元器件的应力分析法是分析电子系统可靠性的一种重要方法，基于应力分析法并根据GJB/Z 299C-2006《电子设备可靠性预计手册》，对星载偏振成像仪供配电系统各组成部件的电子元器件进行失效率计算，并结合系统结构框图对系统的可靠度进行分析。分析结果表明，采用冷贮备的冗余设计方式可以明显提高系统的可靠度。

星载测风干涉仪采用临边观测模式测量大气气辉谱线的多普勒频移来实现大气风场探测，干涉仪有效覆盖性会受到探测目标源及卫星平台模式的限制，在卫星任务规划前端对观测数据进行分析，判断其是否满足科学目标，对风场数据应用具有重要意义。首先，建立了临边观测几何模型，对卫星运行期间仪器的临边切点分布情况进行仿真；其次，探讨了影响仪器有效观测的主要因素，并以昼气辉探测为例，分析在不同时段下，太阳入射角与干涉仪有效时空覆盖性之间的关系；最后使用分离变量法研究卫星轨道参数对测风干涉仪有效覆盖性的影响，并评估不同轨道参数下的干涉仪对欧亚大陆的覆盖百分比。结果表明：1）影响仪器有效观测的因素主要为太阳天顶角和太阳散射角，太阳入射角影响切点纬度覆盖范围和切点地方时；2）卫星轨道倾角和轨道高度共同决定仪器有效覆盖效率，且轨道倾角为欧亚大陆覆盖百分比的主要影响因素，当轨道倾角在60°~80°之间时，覆盖百分比可达到百分百。文中为星载干涉仪的后续设计及性能评估提供了观测几何框架，实现了载荷观测覆盖效能的定量分析，且该模型具备泛用于其他各类大气光学遥感载荷观测模式分析的能力。

针对目前利用有限元方法分析星载光电跟瞄转台动态特性时存在的建模失真问题，提出使用广义弹簧单元对轴承和锁紧机构等效建模，并通过定义模态阻尼比，精确模拟转台的固有频率及响应特性。通过理论计算和基于模态试验数据的参数辨识，确定各等效单元刚度；通过基于扫频试验数据的参数辨识，确定结构模态阻尼。基于建立的等效有限元模型进行仿真分析，模态分析中前6阶固有频率与试验结果的最大偏差为5.1%，谐响应分析中X、Y、Z三个主方向的最大响应与试验结果的最大偏差为3.2%，固有频率与响应一致性良好，均在允许的误差范围内。说明使用广义弹簧单元对轴承和锁紧机构进行等效建模，通过模态和扫频试验数据确定转台刚度和阻尼特性是可行的，对同类型转台的建模仿真有一定借鉴作用。