【作者】 颜蕊；

【导师】 张景发；

【作者基本信息】 中国地震局工程力学研究所 ， 防灾减灾工程及防护工程， 2010， 博士

【摘要】 中国电磁监测试验卫星(CSES)是中国计划发射的第一颗用于电离层特性及电离层地震电磁效应研究的空间探测卫星,已被国防科工局列为“十二五”首批发射的民用卫星。卫星地面应用系统是整个卫星工程发展的必要环节,为保障卫星有效在轨运行,并使卫星接收到的数据发挥应有的作用,需要在确立卫星项目的同时,完成卫星地面应用系统立项工作。因此本文是在国内没有成熟经验可借鉴、国外相关资料难获取的条件下,基于中国电磁监测试验卫星(CSES)工程立项的迫切需要,结合国家关于民用卫星地面资源合理配置、统筹规划的要求开展有关地面应用系统的关键技术研究。本文主要研究三个关键问题:数据下传是否干扰探测数据、卫星地面接收站布局设计以及电磁探测数据的有效应用。三个问题之间是相互影响和制约的。数据下传若存在干扰,除了影响探测数据的质量,也会影响到地面应用系统中地面接收站的布局,因此文中首先从数据应用、电波传播特性、电磁兼容性仿真模拟及试验测试等多个方面对数据下传干扰问题进行了判定;在排除数传干扰疑虑后,对中国电磁试验卫星地面站布局方案进行了研究和设计,合理的布局设计有助于数据的高效获取;有效数据和干扰数据的处理方法研究及结果分析,既可帮助判定数传干扰是否存在,也可为数据的有效应用提供重要的参考。本文以上内容的研究成果和结论为中国电磁监测试验卫星及其地面应用系统的研发提供了重要的参考依据。现将主要研究成果和结论摘要如下:(1)收集整理了研究所需的资料和数据。本文研究内容可借鉴的资料甚少,研究前期获取了与电磁卫星及其地面应用系统相关的关键资料和文献,并进行了系统全面地总结和分析,为本文的研究工作奠定了重要基础,也为CSES的研发积累了宝贵的经验。(2)全面深入地研究了“数据下传是否干扰探测数据”的问题,提出了避免数据下传干扰的措施和建议。首次将“探测双星”数据与DEMETER卫星数据结合,用于数据下传干扰问题的研究,从数据应用的角度,排除了数据下传对探测数据干扰的疑虑。分析了电离层电波传播特性,并估算了电离层对X波段传播链路的影响,得出数据下传过程与电离层之间不会相互干扰的结论。根据CSES设计指标,对星上数传发射机和探测设备之间的电磁兼容性(EMC)进行了仿真计算,得出:在感应式磁力仪满足距离数传发射机电源线1.2m以上时,星上数传发射机与探测设备便能满足EMC兼容。借助新研制的某X波段数传发射机进行EMC试验测试,测试结果表明:数传发射机电源线可能会对探测设备造成电源线传导辐射干扰;频率流程设计不当时,谐波成分可能会干扰GPS掩星双频接收机,但这些问题都可在数传发射机设计过程中采取一定的措施加以避免。基于以上研究结果,提出了避免数据下传干扰的相关措施和建议,包括:星上各载荷位置的科学布局、发射机指标设计、发射机电磁兼容性设计、数传发射机与探测设备的兼容试验以及运控指令调整等。针对“数据下传是否干扰探测数据”的问题,本文采用探测数据处理和分析、电磁波传播特性分析、电磁兼容预测仿真和试验测试相结合的方式进行综合研究,成为解决这一问题最有效的途径之一。文中对电磁卫星数传干扰问题的判定,排除了地面接收站布局的疑虑,有助于地面站优化选择;此外,提出的避免数据下传干扰的措施和建议也在一定程度上为CSES的研发提供了重要参考。(3)根据CSES的行业需求,结合国家关于民用卫星地面资源合理配置、统筹规划的要求,首次提出了CSES地面站布局方案。在确定了数据下传不会干扰实时探测数据的前提下,对CSES地面站布局进行研究和分析。首先收集整理了地面站布局需要考虑的一些约束条件;以调查问卷的方式统计出约束条件的优先级,并将相关数据存入数据库;理清了约束条件之间的相互影响、制约关系,基于约束条件及其之间的相互关系建立优化选址数学模型。利用GIS空间分析技术、结合STK轨道仿真模拟,对地面站优化选择模型进行分析解算,提出了电磁卫星地面接收站的布局方案,主要包括:①单站模式,建议优先选择在北京采取新建或借助已有的卫星地面接收站完成接收任务;②对称模式:建议沿东西向建设两个对称分布的接收站:西部需新建站,新建站范围在91°20′34″E～94°36′27″E以及33°17′20″N～34°29′21″N之间;东部建议在山东禹城建站;③V形模式,优先选择在库尔勒、绥化、肇庆三个地方建V形模式的地面接收站组合;④四站模式,建议的最佳地面站组合为:拉萨、绥化、新丰江、库尔勒。并根据布局方案解算过程,提出了通用性的针对CSES地面接收站选址的技术流程。鉴于目前还没有关于地面站选择的系统性研究,本文的这部分研究工作在国内尚属首次,以期为决策者提供较好的参考方案。(4)建立了电离层等离子体参量观测模型。将DEMETER卫星探测的连续三年等离子体不同参量,通过插值计算完成时空统计,建立了电子、氢离子、氦离子和氧离子数密度的全球观测数据统计模型,并分析其规律特性,对不同离子的全球分布特性取得了进一步的认识,包括:赤道异常特征、逐年变化、不同地磁季节特征等。对某区域一年内重访轨道,按不同地磁季进行了处理和特征分析。这些分析内容及规律总结是对当前主要以电子浓度总数(TEC)为观测参量进行电离层特征研究的一个很好地补充,在一定程度上丰富了前人的研究成果。(5)探索了地震前空间电离层等离子体参量的异常现象。利用时空演化分析、长时间序列分析和多参量轨道对比等方法,探究了汶川、智利和海地三个地震震前可能与地震有关的电离层等离子体参量异常现象,并总结其规律性,如:震前1～3天和震前8～10天异常现象比较集中;NO+、Ne和Ti三个参量观测到的异常现象较多;NO+和Ti两参量异常现象出现的时间和地点相关性比较高;等离子体参量异常具有很强的局部性等。这些探索工作和规律总结,为地震前空间电离层异常现象的监测研究工作积累了经验、教训,为CSES地面应用系统中数据的有效处理和应用奠定了一个初步的基础。本文研究内容和成果已在CSES及其地面应用系统设计研发过程中得以采用,在电磁卫星推进工作中发挥了重要作用。更多还原

【Abstract】 China Seismo-Electromagnetic Satellite (CSES) is the first satellite in China which aims to research ionospheric characteristic and seismoelectromagnetic effects in ionosphere, and will be launched in 5 years. The satellite ground application system (GAS) is necessary part in satellite project developing. In order to ensure satellite trouble-free operation, some researches on ground application system have to be carried out. Based on the urgent need of the project approval for China Seismo-Electromagnetic Satellite (CSES), this paper has made some researches on the key technology of the ground application system (GAS) under the conditions that there is no ripe experience to learn at home and the critical information is hard to obtain abroad.If interference is produced when data are transferred to ground receiving stations, the detection data will be influenced and the layout of ground receiving stations will be restricted. Therefore, firstly, the doubt that the data is disturbed by the downlink is excluded from the perspective of data application, ionospheric characteristic, analog simulation and test. After eliminating the doubt of interference caused by downlink, the layout of ground receiving stations is designed and put forward. The data-processing and result analysis are carried out in above courses. The outcome and conclusion of above researches are important reference for development of CSES and its ground application system.The main work of this paper is as follows:(1) The exiguous and required data and information are collected and analyzed.The data which can be used in the paper is less. Some vital data and related information about electromagnetic satellite and its ground application system are collected, and then analyzed comprehensively. It lays the foundation for research in this paper, and accumulates experience for the development of CSES in the future.(2) The problem that whether the data is disturbed by the downlink is studied thoroughly. And some advices to avoid the downlink disturbance are presented.In this paper, the data of“Double Star”are applied to the study of that whether the data is disturbed by the downlink for the first time. Combine with the analysis of DEMETER data, the doubt that the data is disturbed by the downlink is excluded from the perspective of data application. And then the characteristics of the radio propagation in ionosphere are analyzed and the impacts on X band propagation link caused by ionized layer are estimated, and the results show that the ionized layer does not disturb the data downlink each other. According to the preliminary index of the CSES, the EMC simulation is calculated between digital transmitters and sensors on satellite, and the conclusion is drawn that the EMC is satisfied between digital transmitters and sensors when the IMSC is at least 1.2m away from the digital transmitter’s power line. Moreover, the ongoing X band digital transmitter is used to test the EMC, and which show that the digital transmitter’s power line probably causes conducted interference to sensors and harmonic component probably disturb the GPS occultation dual frequency receiver if the frequency flow is improperly designed. However, all the problems above can be avoided by taking some measures in the process of designing the digital transmitter. Based on the analysis of all above results, some related solutions to avoid the data downlink disturbance are presented as follows: scientific layout of the payloads on satellite, the EMC and indicator design of the transmitter, compatibility experiment between transmitter and sensors and the operational control command adjustment etc.According to the problem that whether the data is disturbed by the downlink, some methods are used to process the study such as exploration data analysis, electromagnetic waves propagation analysis, and the EMC simulation test. This is one of the most effective methods to solve the problem. Moreover, it is helpful to select ground receiving stations optimally, and the solutions to avoid the data downlink disturbance provide important references to the research and development of the CSES practically.(3) The layout solutions of ground receiving stations are presented according to the industry needs of CSES.First, the constraints of the ground receiving stations layout are analyzed, and the priority level is work out statistically based on the questionnaire. The related data are collected and stored in database. The relationships among constraints are cleared. Based on the relationship and constraints, the mathematical model of optimal location is built. Using GIS spatial analysis and orbit simulation, the model of optimal location is analysis calculated. The specific layout solutions are as follows:①single station model: Beijing is the first choice in single station model, constructing new ground station or using already existing ground are adopted to receiving data;②symmetrical model: building a new station in area A with the extent between 91°20′34″E～94°36′27″E and 33°17′20″N～34°29′21″N and the other area B in YuChen;③V-type model: building three stations in Kuerle, SuiHua, ZhaoQing;④four stations model: The best layout group is LaSa, SuiHua, XinFengjiang, Ku’erle. Then according to the calculation procedure of the solutions, a general station selection flow for the CSES is put forward. In light of current situation, there is no such systematic research about the ground receiving station selection. The research work in this paper is carried out for the first time in China and provides important references to the decision makers. (4) The plasma observation models in ionosphere are built and analyzed.A global observation data statistic model of Ne, NH+, NHe+, NO+ is built and its characteristic is analyzed. The spatial and temporal statistics is done by calculus of interpolation on the different plasma parameter derived from DEMETER for three consecutive years. The global distribution character of the different ion is further comprehended. The revisited orbits in an area for one year is processed and analyzed by different geomagnetic seasons. The analysis results are well complementary for current research which mainly focused on the research of TEC in ionosphere. This paper enriches the former study to some extent.(5) The abnormal phenomena in ionosphere before earthquakes are explored and analyzed.Using the methods of spatial-temporal evolution analysis, long time series analysis and orbit comparison of multi-parameter, the related abnormal phenomena in ionosphere are studied before earthquakes in WenChuan, Chile and Haiti. The law is summarized, such as: The anomalies are appeared frequently in 1~3 days and 8~10 days before earthquakes; The anomalies are appeared frequently in parameter of NO+、Ne and Ti; The time and location which NO+ and Ti appear are bound up with each other; and the plasma parameters have strong locality. All the research above accumulate experience and lessons for observing abnormal phenomena in ionosphere before earthquakes and lay the preliminary foundation for the application of the CSES data in future.The research findings and conclusions in this paper have been adopted in the development of ground application system of CSES, and have practical significance.更多还原