太阳X-EUV成像望远镜的移动补偿系统

卫星帆板转动和自身颤动会导致太阳X射线-极紫外射线(X-EUV)成像望远镜的成像质量下降.用移动补偿系统控制相机的CCD驱动器,使势阱转移到相邻相的位置上,转移的方向正好与图像在传感器上移动方向一致,使得图像的每个光子在移动后仍然落入传感器的同一个势阱内,补偿由于帆板移动造成的图像偏移.CCD相移沿列的方向进行,而CCD的列平行于东西向.高精度太阳敏感器使用两轴直角坐标来定位太阳的位置.移动补偿系统只使用其中一个轴向数据,由于南北指向误差远远小于东西指向,因此不对南北指向补偿.该移动补偿系统利用高精度太阳敏感器构成半闭环控制系统,通过偏移CCD势阱来实现一个方向上的移动补偿.该方案可以在不增加成本的前提下,消除长时间曝光过程中的太阳的平移和帆板颤动对图像质量造成的影响,扩大动态观测范围.      

Progress on Space Solar Telescope in 2002-2004

The progress on Chinese Space Solar Telescope (SST) in 2002-2004 is introduced. The documentations on plans and outlines based on the standards of Chinese aerospace industry for SST mission has been fulfilled. The key technical problems of SST satellite platform and payloads are tackled during pre-study stage of the mission. The laboratory assembly and calibration of the main optical telescope of 1.2 m spherical mirror and 1 m plain mirror have been carried out with the accuracy of λ/40 and λ/30, respectively. The prototype at 17.1 nm for extreme ultraviolet telescope is under development and manufacture with a diameter of 13 cm. Its primary and secondary mirrors have a manufacturing error of 5nm with a roughness degree of less than 0.5 nm and a multiplayer reflection factor of better than 20%. The on-board scientific data processing unit has been developed. Prototypes for other payloads such as H and white light telescope, wide band spectroscopy in high energy and solar and interplanetary radio spectrometer have been developed accordingly.     

Identification of uncatalogued LEO space objects by a ground-based EO array

A ground-based electro-optical (EO) array, deployed at the Jilin Space Tracking Base of Changchun Observatory, China, has been in operation since April 2017. The array has 8 small telescopes, each has an aperture of 15 cm and a field of view of 14° × 14°. On average, the array can collect angles data over 3–4 thousand Very Short Arcs (VSAs) of Low Earth Orbit (LEO) space objects each night. Correlation of the VSA angles data with the NORAD catalogue objects results in about 85% of all the VSAs being correlated to NORAD objects. The remaining 15% VSAs angles data could be supposed from uncatalogued objects. The Initial Orbit Determination (IOD) solutions of the VSAs with the range-search method and the association results of the IODs with the geometrical method are presented. The mean IOD success rate is about 91% and the True Positive (TP) rate is more than 86%. In addition, the classical Gauss, Laplace, Gooding and Double-r angles-only IOD methods are applied to process VSA angles data and their performance is assessed. The CBTA method is used to associate the IOD tracks and compared with the geometrical method. A set of procedures for identifying the uncatalogued objects based on the VSA angles data is designed. Processing of the VSA angles data from Aug 4 to Sep 30, 2017 reveals there are possibly 415 uncatalogued LEO objects.     

Investigations of the evolution of optical characteristics and dynamics of proper rotation of uncontrolled geostationary artificial satellites

On the base of the photometrical data an analysis of the periods and light curves of the uncontrolled artificial satellites was performed.     

空间太阳X射线成像望远镜技术

阐述了空间太阳X射线成像望远镜(SXT)在近地环境空间天气观测中的作用和意义。介绍了国内外SXT技术的发展和应用情况，分析了仪器的工作原理、主要观测目标和应具备的基本功能以及关键部件。     

基于空间光学探测的空间目标星等特性分析研究

利用STK对空间目标的轨道特性分析,模拟了太阳与空间目标观测面的夹角,空间目标 在光照区的时间和空间光学望远镜与空间目标的夹角。利用黑体辐射定律,计算太阳在可见 光区域的能流密度,通过建立平面目标可见光辐照度模型,推导了空间目标到达空间光学望 远镜的辐照度模型,建立了一种计算空间目标等效星等模型。通过建立的模型可以对正常工 作的卫星和失效卫星判断区分。     

空间太阳望远镜热光学环境试验技术

空间太阳望远镜在轨期间,空间环境温度变化会严重影响望远镜成像质量,降低分辨率,因此空间太阳望远镜在模拟空间环境下的热光学试验是其研制过程中的关键技术之一。文章介绍了国外部分空间望远镜的热光学试验及低温光学试验设备,并针对国内空间太阳望远镜的研制和试验研究,提出了一些建设性的意见。     

The Swift X-Ray Telescope

he Swift Gamma-Ray Explorer is designed to make prompt multiwavelength observations of gamma-ray bursts (GRBs) and GRB afterglows. The X-ray telescope (XRT) enables Swift to determine GRB positions with a few arcseconds accuracy within 100 s of the burst onset. The XRT utilizes a mirror set built for JET-X and an XMM-Newton/EPIC MOS CCD detector to provide a sensitive broad-band (0.2–10 keV) X-ray imager with effective area of > 120 cm² at 1.5 keV, field of view of 23.6 × 23.6 arcminutes, and angular resolution of 18 arcseconds (HPD). The detection sensitivity is 2×10⁻¹⁴ erg cm⁻² s⁻¹ in 10⁴ s. The instrument is designed to provide automated source detection and position reporting within 5 s of target acquisition. It can also measure the redshifts of GRBs with Fe line emission or other spectral features. The XRT operates in an auto-exposure mode, adjusting the CCD readout mode automatically to optimize the science return for each frame as the source intensity fades. The XRT will measure spectra and lightcurves of the GRB afterglow beginning about a minute after the burst and will follow each burst for days or weeks. Dedicated to David J. Watson, in memory of his valuable contributions to this instrument.     

空间望远镜成像镜调焦机构改进设计与分析

根据已有的研究工作，对成像镜调焦机构系统做了进一步改进，并对模型进行了环境影响分析和考虑接触时的受力分析．文中详细给出了设计的基本原理及设计方法，该机构通过电机驱动丝杠完成对成像镜的移动．由接触分析结果可以看出，考虑接触约束时所计算得到的结果比较符合实际情况，结构的强度满足要求．     

天籁射电阵的空间碎片探测性能分析

提出以曲靖非相干散射雷达作为一种可能的发射源与天籁射电阵组成一套双基地雷达空间碎片探测系统，对该系统的空间碎片探测性能进行计算与仿真分析，包括可探测目标雷达散射截面积(RCS)、天籁射电阵对空间目标与碎片探测时间、探测效率等。分析表明，该系统具有探测直径10 cm以下级空间小碎片的潜力，并在最后提出了一种基于该系统的交叉波束的确定方法及对空间碎片定位的方法。