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题名	单颗导航卫星及探月飞行器的轨道确定研究
作者	祝芙英
学位类别	硕士
答辩日期	2007-06-20
授予单位	中国科学院上海天文台
授予地点	上海天文台
导师	胡小工
关键词	月球重力场 探月飞行器 多普勒 误差源 轨道确定 轨道预报 GEODYN II
其他题名	Orbit Determination for Single Navigation Satellite and Lunar Explorer
中文摘要	After the Global Position System－GPS in the U.S.A、GLONASS in Russia and Galileo navigation plan in the Europe, The China is also preparing to construct our own next Global Navigation Satllite Systerm. The orbit information of the navigation systerm satellite is need for users’ orientation and the relative error will utimately infect the actual users’ orientation precision. In the method of simulation jointing with factuall data calculating, this paper fully discussed the strategy and accuracy of orbit determination for single satellite using the carrier phase and pseudo-range data, without the aid of time synchronization system. We adopted the epoch-difference approach to eliminate the dominant terms of clock errors, by transforming the pseudo-range and phase data into equivalent integral Doppler data, for which we established the simple measurement model. Simulation studies indicated that this orbit determination strategy for one satellite works availably without knowing either satellite clock parameters or receiver clock parameters. In order to confirm the feasibility and the accuracy of the strategy, we try to perform orbit determination for one GPS satellite, analyzing error sources such as data arc lengths, distribution of tracking networks, observation type choices, observation accuracy and the priori orbital errors. The simulating tool is the software we compiled ourselves in the personal computer. The software used for orbit determination is the space data analysis software package GEODYN II developed at Goddard Space Flight Center, NASA. The result indicates that without the information of the clocks’ time differences between the satellite clock parameters and the receiver clock parameters, the RMS of the radial errors is better than 10 meters using three days’ data of a limited tracking network and the user range error (URE) is at about the same level. In addition, in the Chinese Lunar Exploration Mission ‘Chang Er 1’, the task of tracking the spacecraft is mainly dependent on the joint tracking network of United S-Band（USB）and Very Long Baseline Interferometry （VLBI）as a supplement, this paper also analyses the accuracy of orbit determination for Mission orbit and Landing orbit separately not considering both systematic bias and stochastic measurement noise. Specially, the lunar gravity field which is the leading error source for the mission orbit of a lunar spacecraft is discussed, The results indicate that the reduced dynamics method, in which a set of empirical acceleration parameters are estimated along with the initial state vector, can improve the accuracy of orbit determination by absorbing the error of the gravity efficicients. We analyse various error sources that would affect the orbital determination accuracy of the lunar orbiter, moreover, the influences of observation data types、the orbite type and the elevation of station on the accuracy of orbit determination have been investigated.
英文摘要	继美国的全球定位系统（Global Position System－GPS），俄罗斯的GLONASS系统，以及欧盟的Galileo计划之后，中国也正在筹建自己的下一代全球卫星导航定位系统。导航卫星的轨道信息是定位的基本要素，其误差会直接影响到用户定位的精度。 本文采用数值仿真和实测数据分析相结合的方法，考察了在导航星座只有一颗卫星时，不依赖于时间同步系统的卫星定轨策略和精度分析。本文并没有利用地面跟踪站观测数据中的钟差信息，也没有去估算相关钟差，而是直接采用历元间差分算法，即将伪距和相位数据转化为等价的积分Doppler数据，进而消除钟差的主项(低频)误差，并对积分Doppler数据建立测量模型。仿真分析表明，此时不需要知道钟差参数而定轨算法收敛，并且相比于直接利用伪距资料定轨（不解算钟差参数），该算法可以提高定轨和轨道预报精度。为进一步验证此定轨方案的可行性及其定轨精度，本文利用实测的GPS数据进行轨道确定计算。首先，随机选取了GPS星座中的 PRN-02星，详细分析了不同的观测弧段、台站分布、观测类型、观测精度、以及不同的先验轨道误差时的卫星定轨情况。最后，我们选取GPS星座中的多颗卫星进行定轨计算和统计分析。 计算结果表明：在不解算卫星钟差的前提下，采用历元间差分算法，利用国内观测台站三天的观测资料对单颗GPS卫星进行定轨，其平均径向精度优于10米，利用其对国内定位用户的用户距离误差URE可达13.8米。 此外，针对我国正在实施的探月计划“嫦娥一号”工程，本文采用仿真模拟计算的方法，在我国USB测控网和VLBI跟踪网的现有空间分布和尽可能接近真实情况的测量误差源的前提下，采用统计打靶的方法对影响环月、落月飞行器定轨精度的主要误差源进行讨论和分析，结果表明：月球重力场误差是影响探月飞行器定轨精度的主要误差源，采用减缩动力学法定轨能够吸收部分月球重力场误差，可以明显提高探月飞行器的定轨精度和轨道预报精度。最后，探讨了观测资料类型、飞行器轨道类型、月球重力场误差以及观测高度角等对探月飞行器定轨精度的影响，并得出了一些有用的结论。
语种	中文
公开日期	2011-07-01
页码	74
内容类型	学位论文
源URL	[http://119.78.226.72//handle/331011/14686]
专题	上海天文台_中国科学院上海天文台学位论文
推荐引用方式 GB/T 7714	祝芙英. 单颗导航卫星及探月飞行器的轨道确定研究[D]. 上海天文台. 中国科学院上海天文台. 2007.

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