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.

Free-space optical communication (FSO) can achieve fast, secure, and license-free communication without physical cables, providing a cost-effective, energy-efficient, and flexible solution when fiber connection is unavailable. To achieve FSO on demand, portable FSO devices are essential for flexible and fast deployment, where the key is achieving compact structure and plug-and-play operation. Here, we develop a miniaturized FSO system and realize 9.16 Gbps FSO in a 1 km link, using commercial single-mode-fiber-coupled optical transceiver modules without optical amplification. Fully automatic four-stage acquisition, pointing, and tracking systems are developed, which control the tracking error within 3 μrad, resulting in an average link loss of 13.7 dB. It is the key for removing optical amplification; hence FSO is achieved with direct use of commercial transceiver modules in a bidirectional way. Each FSO device is within an overall size of 45 cm × 40 cm × 35 cm, and 9.5 kg weight, with power consumption of ∼10 W. The optical link up to 4 km is tested with average loss of 18 dB, limited by the foggy test environment. With better weather conditions and optical amplification, longer FSO can be expected. Such a portable and automatic FSO system will produce massive applications of field-deployable high-speed wireless communication in the future.

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。

为了更好地实现对日冕及日冕物质抛射的观测，并使观测角度更加精准，设计了太阳对准系统，利用对准系统对太阳成像，根据探测器上太阳像的圆心坐标判断是否对准并调整日冕仪观测角度。将太阳对准系统应用在三圆盘外掩式日冕仪上进行实验，该日冕仪视场为±20°，工作波段为630~730 nm，F数为4，焦距为38 mm，分辨率为1.2'/pixel。对比了单圆盘外掩体与三圆盘外掩体对外掩体边缘衍射光的抑制能力，并提出一种黑洞检测法对日冕仪总杂散光进行检测。实验结果表明，日冕仪指向精度达到0.11'，三圆盘外掩体边缘衍射杂散光低于单圆盘外掩体边缘衍射光，且日冕仪总杂散光抑制水平达到10^-13量级。杂散光检测方法结果良好，准确性高，对准系统实现了预期功能。

目前，移动测站以其高机动性正逐步成为空间目标监测网络重要的系统组成，应用于空间目标的共视观测与精密跟踪。针对移动测站光电望远镜由于工况的不稳定性以及装调过程中存在的指向误差，文中提出了一种基于星图匹配脱靶量标定的指向误差修正方法。首先，根据编码器轴系定位筛选出定标星群并进行资料归算；其次，采用面向脱靶量标定的快速星图匹配算法识别出与测量恒星相匹配的定标星坐标，并作为理论位置；最后，将多颗测量恒星坐标带入脱靶量标定指向修正数学模型对望远镜的指向进行拟合与标定。实验结果证明：采集一组序列图像对光心指向进行修正，单帧图像的修正周期约为2.2 s，从第10帧后修正量基本趋于稳定。对全天区典型分布的一批子天区进行指向修正，指向误差均值由修正前的124.24″提高至4.97″，标准差从41.50″提高至4.76″。综上所述，基于星图匹配脱靶量标定的指向误差修正方法对于提高测站望远镜的指向精度效果显著，且该方法的修正过程与望远镜机架结构无关，因此也可适用于不同机架结构的望远镜指向修正。

在面阵扫描成像激光雷达中，阵列光束照明与棱镜扫描相结合实现了高能量利用率、高分辨率和宽探测视场，但阵列子光束倾斜入射棱镜，破坏了光束传输的旋转对称性，棱镜对子光束偏转能力存在差异，规则光束阵列产生了形状畸变，导致光束指向误差，影响点云位置精度。首先，将阵列光束与棱镜结合的圆锥扫描方式分解为多角度入射多波束并行扫描，通过所有子光束的传输特征来综合表征阵列光束传输特征；然后，采用三维矢量光学方法推导了阵列光束在棱镜中的传输过程，建立了子光束指向变化与棱镜扫描角度的关系；最后，通过对机载激光雷达棱镜扫描成像过程的数值仿真，建立了光束指向变化与点云数据质量的联系。仿真结果表明：阵列光束(3×3)棱镜扫描系统在航高0.5 km时，光束阵列畸变导致平面误差RMS约为5 cm，并随航高呈线性变化；斜率约为0.1 m/km，并随着阵列光束规模和子光束角间距增加点云平面精度随之下降。通过对棱镜扫描过程中光束阵列畸变规律掌握，为后续机载飞行试验数据的校正、阵列光束结合多棱镜扫描系统的设计提供了基础。