【作者】 董雪；

【导师】 赵有；

【作者基本信息】 中国科学院研究生院(长春光学精密机械与物理研究所) ， 电路与系统， 2014， 博士

【摘要】 随着空间碎片数量的增多，空间碎片严重威胁航天器的安全运行和人类太空活动开展，空间碎片监测、预警受到各国的广泛重视。空间碎片激光测距技术与其他地基观测设备相比，具有数据精度高、同时提供目标方位、高度、距离信息等优点，不仅能够用于空间碎片监测，提高空间碎片定轨精度，而且还可以为其他监测手段提供标校，对空间碎片监测、预警等研究具有重大意义。本文将传统用于合作目标的激光测距技术引入到非合作目标监测领域，基于长春人造卫星观测站现有60cm卫星激光测距平台，针对空间碎片目标运行速度快、预报精度差、有效数据难以提取等一系列问题，在国内首次开展高重复频率空间碎片激光测距研究，建立了高重复频率、高精度、高灵敏度、高自动化的空间碎片激光测距系统平台，实现对空间碎片目标的观测。实测期间，获得的有效空间碎片观测数据200余圈，最小内符精度RMS为21.5cm，最小雷达散射截面1.2m2,其中晨昏观测数据8圈。获取的目标观测弧段长、作用距离远、观测精度高、有效数据点多、雷达散射截面小、单日观测圈数多，且系统的探测能力延伸到晨昏时段。论文的主要工作内容和成果如下：(1)理论计算并分析空间碎片激光测距系统探测能力，为高重复频率DLR系统设计提供依据。(2)研发高重复频率实时控制子系统，建立独立的高精度时间系统，输出高重复频率点火和距离门控信号，确保数据的实时、稳定、可靠传输及各设备的同步观测。(3)针对空间碎片轨道预报精度差问题，分析两行轨道根数及SGP4模型，并给出了空间碎片目标选取条件，引入回波指数的概念，建立观测目标数据库，提高探测成功率。(4)应用图像处理技术，对实时采集的激光束后向散射CCD图像进行边缘信息提取，拟合激光束光尖与接收视场中心的偏差量，实时修正激光束指向。(5)针对空间碎片漫反射回波弱问题，研制高灵敏度、量子效率高、噪声低、响应速度快的单光子Geiger模式APD探测器，接收微弱光子回波。(6)采用多次迭代滤波算法，解决高重复频率DLR数据提取困难问题，快速实现低信噪比下有效数据的识别。实测结果表明，高重复频率空间碎片激光测距，以其数据精度高、数据点数多等优点，将在空间碎片监测和预警等领域发挥重要的作用。更多还原

【Abstract】 With the increase in the amount of space debris, space debris poses a seriousthreat to spacecraft operation and human space activities. Space debris monitoringand early warning is widely concerned by researchers all around the world. Spacedebris laser ranging (DLR) could be used not only in monitoring and improving thedebris orbit accuracy but also in calibration for other monitoring method. It issignificant to the study on space debris.This paper is based on Changchun60cm aperture laser ranging system, aimingat a series of problems such as space debris objects’ angular rate, prediction accuracy,signal identification, to establish space debris laser ranging (DLR) system with highrepetition rate, high precision, high sensitivity and high automation, realizedeffective observation at last. It is the first research on high repetition DLR in China.The system has achieved nearly200passes, with the minimum RCS1.2m2, bestminimum range precision of21.5cm, in which8twilight passes. The maincontributions of this dissertation can be summarized as follows:(1) Calculation and analysis of DLR system detection ability, in order to providethe basis for the design of high repetition DLR system.(2) Developed high repetition real-time control subsystem, established highaccuracy independent timing system, export high frequency firing and range-gatesignal, to ensure real-time, stable, reliable data transmission and synchronous observation.(3) According to the analysis of two line elements (TLE) and the SGP4model,the space debris object selection criteria is given. By introducing the concept ofreturn index, established the target database, to improve the detection rate of success.(4) Applied image processing technique to extract edge information gatheredfrom the real-time CCD image, so as to exactly calculate the laser beam tip deviationfrom FOV center, corrected the real time laser beam pointing.(5) For the problem of weak space debris diffuse reflection, the high sensitivity,high quantum efficiency, low noise, single photon Geiger-mode APD detector wasdeveloped to receive weak photon returns.(6) The multiple filtering algorithm was improved, in order to solve the highrepetition frequency DLR data extraction problem, so as to realize data identificationunder low SNR.In short, high repletion DLR will play an important role in the field of spacedebris monitoring and warning.更多还原