基于星载GPS的低轨卫星非差动力学定轨方法研究

发布时间：2018-02-27 07:10

本文关键词： 低轨卫星星载GPS 非差动力学定轨 APOD GRACE　出处：《中国地质大学(北京)》2017年硕士论文　论文类型：学位论文

【摘要】：低轨卫星因为其轨道高度的特殊特点,是最适合承担应用与科学实验的平台与载体,这使得低轨卫星具有重要的战略意义和科研价值。低轨卫星高精度轨道确定是保证其顺利完成各项科学实验任务的前提与基础,星载GPS因其成熟的技术和无可比拟的优势成为实现低轨卫星精密定轨的重要手段。本文围绕基于星载GPS的低轨卫星非差动力学定轨展开研究,通过理论研究,软件实现相关关键算法,并以星载GPS数据为例,分析低轨卫星轨道特点、验证本文理论和软件数据处理精度,在此基础上本文给出一些重要结论。本文的具体工作如下:(1)介绍了星载GPS的观测量与观测方程,重点给出了星载双频接收机无电离层组合观测模型,并分析了其观测误差源和各项误差的改正方法,从观测模型的角度为接下来的定轨问题研究打好基础。(2)从动力学信息和卫星运动状态信息两方面入手详细阐述了低轨卫星动力学精密定轨的原理,给出了轨道求解的数学过程。针对最小二乘批处理方法中钟差参数过多的问题,给出了钟差约化理论模型的公式推导过程和软件实现方法。(3)研究拉格朗日插值法和切比雪夫插值法对IGS精密星历拟合精度的影响,实验证明:采用13阶拉格朗日插值或切比雪夫插值都可以达到低轨卫星精密定轨对GPS卫星位置的精度要求;同时,分析了线性插值和三次样条插值对不同时间间隔的IGS精密钟差的插值性能,实验证明在相同情况下,线性插值法比三次样条插值法的插值精度要高,而且在低轨卫星精密定轨中可采用IGS的30秒精密钟差进行插值,以求得所需时刻的GPS卫星钟差。(4)参与编写、调试、完善并测试了一套基于非差动力学方法的低轨卫星定轨软件平台,本文介绍了软件的功能结构和定轨流程;利用该软件平台分别对国产微纳卫星APOD和国际知名的重力卫星GRACE进行了多天轨道的计算,并对定轨成果进行了精度验证。结果表明:APOD卫星伪距和相位观测值的内符合精度分别约为2m和2.5cm,符合该卫星科研项目需要,基于轨道重叠弧段检验的精度水平优于分米级;GRACE-A卫星伪距和相位观测值内符合精度分别在0.9m和1.2cm,基于轨道重叠弧段检验的精度水平在7cm左右,与PSO标准轨道比较,其三维位置精度约为12cm。
[Abstract]:Because of its special characteristics of orbital altitude, Leo satellites are the most suitable platform and carrier for applications and scientific experiments. This makes the Leo satellite have important strategic significance and scientific research value. The high-precision orbit determination of the Leo satellite is the premise and foundation to ensure the successful completion of various scientific experimental missions. Spaceborne GPS, due to its mature technology and unparalleled advantages, has become an important means to achieve precise orbit determination of Leo satellites. This paper focuses on the study of non-differential dynamic orbit determination of Leo satellites based on spaceborne GPS. The key algorithms are realized by software. Taking spaceborne GPS data as an example, the characteristics of Leo satellite orbit are analyzed, and the theoretical and software data processing accuracy are verified. On this basis, some important conclusions are given. The main work of this paper is as follows: (1) the observations and equations of spaceborne GPS are introduced, and the ionospheric combined observation model of spaceborne dual-frequency receiver is given. The source of observation error and the correction method of each error are also analyzed. From the point of view of observation model, this paper lays a good foundation for the next research on orbit determination. (2) the principle of dynamic precise orbit determination of Leo satellite is described in detail from two aspects: dynamic information and satellite motion state information. The mathematical process of orbit solving is given. In order to solve the problem of excessive clock error parameters in the least square batch processing method, The formula derivation process and software implementation method of bell difference reduction theory model are given. The influence of Lagrange interpolation method and Chebyshev interpolation method on the precision of IGS precision ephemeris fitting is studied. The experimental results show that 13 order Lagrangian interpolation or Chebyshev interpolation can meet the precision requirements of precise orbit determination for GPS satellites. The interpolation performance of linear interpolation and cubic spline interpolation for IGS precision clock difference with different time intervals is analyzed. The experimental results show that the interpolation accuracy of linear interpolation method is higher than that of cubic spline interpolation method under the same condition. Moreover, the 30 seconds precise clock difference of IGS can be used to interpolate the precise orbit determination of the Leo satellite, so as to obtain the GPS satellite clock difference of the required time. A software platform for Leo satellite orbit determination based on non-differential dynamics method is developed and tested. The function structure and orbit determination flow of the software are introduced in this paper. The software platform is used to calculate the multi-day orbit of the domestic micro-nano satellite APOD and the internationally famous gravity satellite GRACE, respectively. The precision of orbit determination is verified. The results show that the internal coincidence of the pseudo-range and phase observation values of the 1: APOD satellite is about 2m and 2.5 cm respectively, which is in line with the need of the satellite scientific research project. The accuracy level of orbit overlap arc test is better than that of decimeter GRACE-A satellite pseudo-range and phase observation are 0.9m and 1.2cm respectively, and the accuracy level based on orbit overlap arc test is about 7cm, which is compared with PSO standard orbit. The 3D position accuracy is about 12 cm.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P228.4

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