1.27 μm波段O₂（a¹?_g）气辉的辐射强度高、自吸收效应弱，是反演临近空间大气温度的理想目标源。基于O₂分子气辉光谱理论以及“剥洋葱”算法，利用扫描成像大气吸收光谱仪（SCIAMACHY）的近红外临边观测数据，成功反演50~100 km区域的大气温度廓线。与SABER、ACE-FTS及激光雷达的观测结果对比表明，在55~85 km的切线高度范围内温度测量误差优于±10 K，而在55 km以下与85 km以上空间区域，由于受到自吸收效应、大气散射以及OH气辉的光谱污染等干扰，温度反演结果出现显著偏差。

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: The space gravitational wave detection telescope is one of the core payloads of the gravitational wave detection satellite, simultaneously expanding and contracting the transmitted beam. Optical path stability is one of the core indices for the telescope, closely related to its structural stability. To meet the ultra-high path stability and structural stability requirements posed by the gravitational wave detection mission, it is essential to study the structural deformation measurement of the telescope. Currently, there are still several shortcomings in the research of multi-degree-of-freedom deformation measurement methods for gravitational wave detection telescopes, such as inaccurate selection of measurement points, inability to decouple multi-degree-of-freedom coupling, and unclear identification of error sources in multi-degree-of-freedom measurement. This paper deeply investigates the high-precision measurement of structural deformation of space-borne telescopes designed for space gravitational wave detection. It preliminarily establishes a framework and method system for measuring the structural deformation of space-borne telescopes, theoretically describing the measurement principle of the method. The feasibility of this method applied to space gravitational wave detection is verified through simulation analysis and error decomposition. The paper focuses on resolving the issue of decoupling multiple degrees of freedom, establishing a mathematical model using analytical methods, and conducting preliminary validation using Zemax. Finally, noise analysis of the measurement system is carried out, with experimental testing of the main noise components in the measurement system, validating the correctness of the theoretical noise model proposed in this paper. The experimental results show that near 1 Hz, the displacement noise background of the single-link interferometer is 100 pm/Hz^1/2. At 1 mHz in the low-frequency range, the displacement noise background reaches 10 nm/Hz^1/2. The noise level of the measurement system below 1 mHz is mainly limited by environmental temperature noise, while above 10 mHz, it is primarily constrained by laser frequency noise, phase acquisition background noise, and vibration noise. During the development phase of the space gravitational wave detection telescope, the research on this measurement method is expected to fulfill the telescope's multi-degree-of-freedom deformation measurement needs. It also provides data feedback for telescope design and offers guidance for the study of the telescope's optical path stability.

Taking the LISA system as a reference, the phase noise of the inter-satellite transmission needs to be less than 1 pm. Research has shown that the defocus and the astigmatism are the main aberrations affecting jitter noise at a distance of 2.5×10⁹ m. There is a deviation between the phase stationary point and the origin position. To minimize the phase noise, the telescope angle needs to be adjusted. The gravitational wave detection at the phase stationary point can effectively reduce the phase noise and the requirements of the telescope exit pupil wavefront RMS. The large defocus and small coma can make the phase stationary point close to the optical axis and increase the received laser power.

Light-field fluorescence microscopy (LFM) is a powerful elegant compact method for long-term high-speed imaging of complex biological systems, such as neuron activities and rapid movements of organelles. LFM experiments typically generate terabytes of image data and require a substantial amount of storage space. Some lossy compression algorithms have been proposed recently with good compression performance. However, since the specimen usually only tolerates low-power density illumination for long-term imaging with low phototoxicity, the image signal-to-noise ratio (SNR) is relatively low, which will cause the loss of some efficient position or intensity information using such lossy compression algorithms. Here, we propose a phase-space continuity-enhanced bzip2 (PC-bzip2) lossless compression method for LFM data as a high-efficiency and open-source tool that combines graphics processing unit-based fast entropy judgment and multicore-CPU-based high-speed lossless compression. Our proposed method achieves almost 10% compression ratio improvement while keeping the capability of high-speed compression, compared with the original bzip2. We evaluated our method on fluorescence beads data and fluorescence staining cells data with different SNRs. Moreover, by introducing temporal continuity, our method shows the superior compression ratio on time series data of zebrafish blood vessels.

大口径空间光学望远镜是实现高分辨率遥感与高灵敏度探测的重要科学仪器。传统的整体式望远镜口径超过4 m将难以突破现有运载器整流罩有效包络的限制，采用分块式的技术手段可以在满足运载能力的前提下实现口径最大化，是解决当前望远镜高分辨率与高信息收集能力的最优选择。文章先从部署形式上对分块式空间望远镜的国内外研究现状进行了梳理，归纳出分块望远镜在技术实现路线上的技术类型和特点，分别对高精度机构展开技术、机器人智能装配技术、波前检测与调控技术以及超轻可调分块镜技术进行了技术内涵及实现技术途径分析，最后面向未来远景目标，对分块式空间望远镜的技术发展作了展望。

针对云层日变化、云类型、云相态、云光学厚度等特征差异带来的光谱差异，导致传统阈值算法对云识别精度不高的问题，文章提出了一种顾及样本优化选择，耦合物理阈值方法和机器学习的云检测算法模型，利用“葵花8号”卫星（Himawari-8）数据进行日间云检测。通过样本优化选择，使样本中尽可能包括不同情形下的云特征，为机器学习模型提供良好的样本基础，增加模型泛化能力；同时输入特征除了考虑反照率、亮温、亮温差以及天顶角等因素外，还加入了基于反照率和亮温差的物理阈值方法云识别结果；最后基于极限随机树模型进行云检测。结果表明：模型云检测交叉验证精度为96.41%，总漏检率和总虚检率分别为2.08%和0.91%；通过云-气溶胶激光雷达与红外探路者卫星观测（CALIPSO）产品数据进行对比分析，结果显示云检测总体精度为97.1%。