【作者】 易重海；

【导师】 朱建军； 陈永奇；

【作者基本信息】 中南大学 ， 大地测量学与测量工程， 2011， 博士

【摘要】 实时精密单点定位技术(Real Time Precise Point Positioning,简称RT-PPP)已成为当前GNSS (Global Navigation Satellite System)领域的研究热点,也将是目前乃至未来实时高精度动态定位的主要技术手段之一。本论文对GPS精密单点定位技术中卫星钟差插值误差、高精度高采样率卫星钟差求解方法、实时精密单点定位中周跳探测与修复算法以及基于区域GPS连续运行跟踪站(Continuously Operating Reference Stations,简称CORS)网络和IGU超快轨道建立区域实时精密单点定位系统等四个方面进行研究。论文的主要结论如下：(1)PPP技术采用非差观测值进行数据处理,卫星钟差插值误差不能像GPS相对定位模式那样可以被消除,所以卫星钟差插值误差直接影响PPP定位精度。作者对卫星钟差插值误差进行分析,指出PPP定位的误差源应包括卫星钟差插值误差,以完善当前的PPP技术的误差分析理论。(2)针对卫星钟差插值误差,提出了一种顾及卫星钟差插值误差的观测值随机模型。该模型在卫星钟差采样间隔较大(如5min)时,可以显著提高PPP定位精度；而当卫星钟差采样间隔足够小的时候(如30s),钟差插值误差影响比较小,则可以不考虑。(3)高采样率卫星钟差是削弱PPP定位中卫星钟差插值误差的最有效方法。本论文提出了一种改进的高采样率卫星钟差求解方法,该方法具有算法简单、计算量小、运算速度快、精度高等优点,能够胜任连续的长时间高采样率卫星钟差求解,并可以满足厘米级高精度PPP定位的需要,但其缺点是不能应用于时间传递方面的应用。(4)数据质量控制是获取高精度位置信息的关键因素之一,文章提出了一种适用于实时GPS精密单点定位的周跳探测与修复新算法。该算法充分利用实时精密单点定位中必需的高精度GPS卫星轨道和高精度、高采样率卫星钟差信息,仅利用当前历元与前—(或者几个)历元观测值进行周跳探测与修复。试验结果表明：新算法能够对实时PPP中的周跳进行快速准确的探测与修复,并能够处理P码观测值精度较差和无P码观测值的接收机观测数据。(5)提出了一种基于IGS发布的IGU超快轨道产品和区域CORS网络数据建立区域GPS实时精密单点定位系统的方法。结果表明：利用本文提出方法建立的区域GPS实时精密单点定位系统,能够提供厘米级实时精密单点定位结果,具有算法简单、对系统软硬件要求低、应用成本低等优点,且系统的应用范围可以扩展至该区域数百公里内的广大区域。(6)利用Fortran语言开发了一套GPS精密单点定位数据处理软件,该软件可以进行事后或者实时动态、静态精密单点定位及高精度、高采样率卫星钟差估计。数值分析表明,该软件的定位结果精度达到了当前国际同类研究水平。更多还原

【Abstract】 Real-time precise point positioning (RT-PPP) has been one of research focus in current Global Navigation Satellite System (GNSS) community, and will be one of the main techniques for real-time precise kinematic positioning in the present or even for the future. In this thesis, satellite clock interpolation error, precise high-rate satellite clock bias computation method, real-time cycle slip detection and repair algorithm for PPP and establishment regional RT-PPP system based on regional GPS Continuously Operating Reference Stations(CORS) network and International GNSS Service(IGS) Ultra-rapid product have been studied comprehensively. The main conclusions and contribution are as following:1) PPP use undifferenced observation for data processing. In PPP, satellite clock interpolation error can not be eliminated as differential GPS positioning, and then deteriorate PPP positioning precision. After analysis of satellite clock interpolation error, the conclusion that satellite clock interpolation error should be included in the PPP error source is drawn, in order to make error analysis theory of PPP more perfect.2) An improved observation stochastic model considering satellite clock interpolation error has been proposed. Experiments shown that this model could reduce the satellite clock interpolation error dramatically for larger time interval clock product (e.g.5 minutes), and then improve the positioning precision while has little improvement for small time interval product (e.g.30 seconds).3) Using high-rate satellite clock is the most effective method to mitigate satellite clock interpolation error for PPP. An improved high-rate satellite clock calculation method was proposed. The new method has several advantages, such as less unknown parameters, simple algorithm, high computation efficiency and high accuracy, and could be used to compute long duration high-rate satellite clock bias for centimeter accuracy PPP. But it can not be used for time application, e.g. time transfer.4) Quality control is one of the key factors for high precision GPS positioning. Anew cycle slip detection and repair algorithm suitable for RT-PPP was put forward. The new algorithm makes full use of precise GPS satellite orbit and clock to detect and repair phase cycle slips using the observations of current and previous one (or several) epoch only. Experiments show that new algorithm can repair cycle slips correctly and rapidly for RT-PPP and has wide range of applications as it can process observation data for receivers of poor accuracy P code observation and non-P code.5) An approach to establish regional RT-PPP system using regional GPS Continuously Operating Reference Stations (CORS) network data and IGS ultra-rapid (IGU) product is proposed. Experiments show that the approach can be used to do centimeter precision RT-PPP positioning, has numerous advantages, such as simple algorithm, low-cost system software and hardware, and can extend PPP service area several hundreds kilometer away from CORS.6) A GPS Precise Point Positoning software was developed using Fortran programming language. The software can conduct post-processing or real-time static and kinematic precise point positioning and compute precise high-rate satellite clock bias. Numerical Results show that the software can achieve high precision PPP positioning result comparable to current international research.更多还原