北斗卫星导航系统性能评估理论与试验验证

发布时间：2018-07-26 12:14

【摘要】：卫星系统性能评估是卫星系统初期设计、研发和部署以及系统升级扩展的主要依据之一,也是卫星系统连续运营重要保障。我国的北斗卫星导航系统采取“先试验、后区域、再全球”的三步走战略,各个阶段的卫星星座设计、性能指标、服务范围等既有承前启后、平稳过渡的作用又有各自特色。因此研究适合于北斗系统的性能评估理论与方法对现阶段的区域系统和将来覆盖全球的北斗卫星系统发展具有重要的现实意义。本文以建立北斗卫星导航系统性能评估体系为目标,系统研究卫星导航系统的基本理论、模型、方法,并自主设计进而研制了以北斗系统为主、兼顾GPS、GLONASS、Galileo的性能评估软件系统,实现了从空间信号层到服务层性能综合评估的较为完善的体系。在此基础上,通过分析处理北斗系统试运行以来的海量实测数据,按系统星座结构变化分阶段对比分析了北斗区域系统基本的性能提升过程,进一步验证了北斗系统性能评估理论、方法和软件系统的正确性。从影响高精度定位的载波观测值的数据质量入手,对比分析相同环境下北斗系统与GPS的载噪比、多路径和噪声水平；开展了短基线相对定位和精密单点定位试验,分析了北斗高精度定位的性能水平。本文主要研究工作及贡献如下： 1、分析总结了GPS、GLONASS和Galileo导航卫星系统性能评估国内外研究现状。从完善现有导航系统的评估理论和方法以及我国北斗卫星系统发展的需求出发,阐述了北斗卫星系统性能评估的理论方法研究和软件研制的必要性。 2、系统研究了以GPS为代表的GNSS卫星系统性能评估基本理论与方法。重点论述了GNSS卫星导航的必备性能指标,包括可用性、精度、完好性和连续性指标定义及相关计算方法。 3、提出了适用于北斗系统空间信号精度的计算方法。北斗区域卫星系统的最大特点是卫星星座主要以GEO和IGSO地球同步轨道组成,其轨道高度的不同导致已有的空间信号误差URE精度计算方法失效。本文对北斗URE精度的统计公式进行了详细推导,同时详细分析论证了北斗用户距离率误差URRE和用户测距加速度的计算方法。然后对实测数据进行了评估,分析得出URE优于1.5米：URRE优于3.00mm/s; URAE优于2.00mm/s2。 4、基于武汉大学“北斗试验跟踪网”观测数据,利用PANDA精密定轨软件获取的精密钟差数据在轨评估了北斗导航星时钟频率稳定度。卫星钟作为导航系统的星上时间基准,是卫星导航系统的核心部分,其性能将直接影响系统的服务精度。本文依靠有限的数据资源利用北斗精密钟差数据综合评估了北斗频率稳定度。北斗在轨卫星大部分原子钟分钟稳定度分钟稳定度达到1-2×10--2,千秒稳达3-4×10-13,万秒稳定度达1-2×10-13量级,天稳定度可达1-2×10-1‘量级。北斗铷钟稳定度水平与GPSBlock Ⅱ A的铷原子钟、GLONASS-M卫星和日本的QZSS星载原子钟性能水平相当,优于GPS Block ⅡA的铯钟,而略差于Block ⅡR铷钟和Galileo铷钟。 5、首次系统分析了北斗空间信号误差的统计特性。利用统计学中的峰度和偏度系数以及Q-Q图对北斗空间信号误差进行正态假设的验证,同时对不同卫星之间的误差相关性进行了假设检验。结果表明北斗空间信号误差分布并不严格服从零均值正态分布,而更接近于学生分布。同时,统计结果表明不同卫星之间的误差相关性很弱。 6、统计分析了自2011年北斗系统试运行以来的PNT性能。本文基于“北斗实验网”对分布在亚太地区的典型监测站的PNT性能进行了分析计算(2012年1月-2013年6月).评估结果表明这些监测站附近北斗系统单频伪距单点定位服务精度已满足北斗服务区内的服务指标。 7、利用本文提出的PNT性能预测方法对北斗当前为区域系统的情况下对服务区内的PNT进行预测,并用实测监测站的数据进行了复核。推算的结果表明,当前北斗系统在中国地区的PDOP值分布大部分达到3～5,三维定位精度优于10米；但范围扩大到整个亚太地区时,在精度处于东经80。和140。开外的大部分地区达不到10米的定位水平；然后针对将来的北斗全球导航系统(3G+3I+27M)星座下的DOP值分布和可能达到的PNT性能进行简单预测,结果表明HDOP将优于1,而VDOP将优于2.0,水平精度优于3米,高程可达4-5米。这一结果表明,2020年建成的北斗系统的PNT性能将与当前GPS相当。 8、首次实现了北斗室外绝对天线相位中心算法并评估了北斗高精度定位性能。本文深入研究了基于机器人的绝对天线相位中心校正理论与方法,并通过实测数据分析与GPS已知天线相位中心进行比较,取得了优于lmm的外符合精度。基于该技术估算的北斗天线相位变化消除了其对北斗高精度定位性能评估的影响。基于该项成果,本文对比分析相同环境下北斗系统与GPS观测数据质量,然后开展了短基线相对定位和精密单点定位的性能测试。结果表明,北斗系统的短基线相对定位可到mm级,精密单点PPP可达到cm级的定位水平,定位性能与GPS基本接近。 9、以北斗性能评估为主,兼顾GPS和Galileo系统,自主设计并研制了卫星导航系统性能评估软件系统,主要研究内容包括：软件总体框架、功能模块、算法流程等。
[Abstract]:The performance evaluation of satellite system is one of the main bases for the initial design, development and deployment of the satellite system and the expansion of the system. It is also an important guarantee for the continuous operation of the satellite system. The Beidou satellite navigation system in China adopts the three step strategy of "first test, post region, and then global", and the design of satellite constellations at various stages, performance index, and service It is of great practical significance to study the performance evaluation theory and method suitable for the Beidou system and to develop the regional system at the present stage and the development of the Beidou satellite system covering the world in the future.
This paper aims at establishing the performance evaluation system of the Beidou satellite navigation system, systematically studies the basic theory, model and method of the satellite navigation system, and designs and develops the performance evaluation software system based on the Beidou system and taking into account the GPS, GLONASS and Galileo, and realizes the comprehensive evaluation of the performance from the spatial signal layer to the service layer. On this basis, by analyzing and processing the massive measured data of the Beidou system, the basic performance upgrading process of the Beidou regional system is analyzed and compared according to the changes of the system constellation structure, and the accuracy of the Beidou system performance evaluation theory, method and software system is verified. Based on the data quality of the observed carrier observation value, the carrier noise ratio, the multi path and the noise level of the Beidou system and GPS under the same environment are compared and analyzed. The relative positioning of the short baseline and the precision single point positioning test are carried out, and the performance level of the high precision positioning of the Beidou is analyzed. The main research work and contribution of this paper are as follows:
1, the performance evaluation of GPS, GLONASS and Galileo navigation satellite system at home and abroad is analyzed and summarized. From improving the evaluation theory and method of the existing navigation system and the demand of the development of the Beidou satellite system in our country, the theory and method research of the Beidou satellite system performance evaluation and the necessity of the software development are expounded.
2, the basic theory and method of performance evaluation of GNSS satellite system represented by GPS are systematically studied. The essential performance indexes of GNSS satellite navigation are discussed emphatically, including the definition of availability, precision, completeness and continuity index and related calculation methods.
3, the calculation method suitable for the precision of the spatial signal of the Beidou system is proposed. The biggest feature of the Beidou regional satellite system is that the satellite constellations are mainly composed of GEO and IGSO geostationary orbit. The difference of the height of the orbit leads to the failure of the existing spatial signal error URE precision calculation method. The statistical formula of the Beidou URE precision is carried out in this paper. In detail, the calculation method of the distance error URRE of the Beidou user and the calculation method of the user range acceleration are analyzed in detail. Then the measured data are evaluated, and the analysis shows that the URE is better than 1.5 m: URRE is superior to 3.00mm/s, and URAE is better than 2.00mm/s2..
4, based on the observation data of the "Beidou test tracking network" of Wuhan University, the clock frequency stability of the Beidou navigation star is evaluated on orbit using the precision clock difference data obtained by the PANDA precision orbit determination software. The satellite clock is the core part of the satellite navigation system, and its performance will directly affect the service precision of the system. Based on the limited data resources, this paper comprehensively evaluates the dipper frequency stability by using the Beidou precision clock difference data. The stability of most atomic clocks in the Beidou on orbit satellites reaches 1-2 x 10--2, a thousand seconds stable up to 3-4 x 10-13, and the stability of ten thousand seconds reaches 1-2 * 10-13. The stability is up to 1-2 x 10-1 'magnitude. The stability of the North dipper rubidium clock is stable. The degree level is similar to that of the GPSBlock II A rubidium clock, the GLONASS-M satellite and the Japanese QZSS spaceborne atomic clocks, which are superior to the GPS Block II A caesium clock, but slightly worse than the Block II R rubidium clock and the Galileo rubidium clock.
5, the statistical characteristics of the spatial signal error of the Beidou are systematically analyzed for the first time. Using the kurtosis and skewness coefficient and the Q-Q map to verify the normal assumption of the Beidou spatial signal error, the error correlation between different satellites is tested. The results show that the spatial signal error distribution of the Beidou is not strictly subject to the error distribution. The zero mean normal distribution is closer to the student distribution. Meanwhile, the statistical results show that the error correlation between different satellites is very weak.
6, the PNT performance of the Beidou system since 2011 was statistically analyzed. Based on the "Beidou experimental network", the PNT performance of the typical monitoring stations in the Asia Pacific region was analyzed and calculated (June, January 2012 -2013). The evaluation results showed that the accuracy of the single frequency single point positioning service accuracy of the Beidou system near these monitoring stations was satisfied. Service indicators in the Beidou service area.
7, the PNT performance prediction method proposed in this paper is used to predict the PNT in the service area under the current situation of Beidou as a regional system, and recheck the data of the measured monitoring station. The results show that the current distribution of the PDOP value of the Beidou System in China is up to 3~5, and the three-dimensional positioning accuracy is better than 10 meters. When extended to the entire Asia Pacific region, the positioning level of most areas with precision in the 80. and 140. opening areas of the East Asia is less than 10 meters, and then the DOP value distribution under the 3G+3I+27M constellation and the possible PNT performance of the future Beidou global navigation system constellation are simply predicted. The results show that HDOP will be better than 1, and VDOP will be better than 2. The accuracy is better than 3 meters and the height can reach 4-5 meters. This result shows that the PNT performance of the Beidou system built in 2020 will be comparable to that of the current GPS.
8, for the first time, the algorithm of the absolute antenna phase center of the Beidou outdoor is realized and the high precision positioning performance of the dipper is evaluated. The theory and method of the absolute antenna phase center correction based on the robot are studied in this paper, and compared with the GPS known antenna phase center by the measured data analysis, the accuracy of the external coincidence is better than that of the LMM. The phase change of the Beidou antenna estimated by this technique eliminates the impact on the high precision positioning performance evaluation of the Beidou. Based on the results, this paper compares and analyzes the quality of the Beidou system and the GPS observation data under the same environment, and then carries out the performance test of the short baseline relative positioning and the precision single point positioning. The results show that the short baseline of the Beidou system is based on the results. The relative positioning can reach the mm level. The precision single point PPP can reach the cm level positioning level, and the positioning performance is basically close to that of GPS.
9, based on the performance evaluation of the Beidou and taking into account the GPS and Galileo systems, the performance evaluation software system of the satellite navigation system is designed and developed independently. The main research contents include the overall framework of the software, the function module, the algorithm flow and so on.
【学位授予单位】：武汉大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：P228.4

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