GNSS地基增强系统完好性监测关键技术研究

发布时间：2018-06-13 23:49

本文选题：完好性监测 + 地基增强系统　；参考：《电子科技大学》2014年硕士论文

【摘要】：导航系统的定位精度、连续性、完好性和可用性等是导航服务性能中最为核心的几个指标,日益受到用户的重视。其中,完好性的性能要求是导航服务性能指标中最难满足的一项。为了提高导航系统的性能,在全球导航卫星系统中,引入BOC信号调制方式,提高卫星星历的预测精度,使用多个频段的载波信号等。在此背景下,地基增强系统为了确保飞机的精密进场与安全着陆,必然要解决其中许多与传播信号相关、与广播数据相关和与测量数据相关的完好性问题。本文主要对地基增强系统的完好性监测关键技术进行研究,主要内容如下:1.本文以飞机精密进场着陆为基础,分析了地基增强系统的整体结构,介绍了参考接收机利用载波相位测量值平滑伪码测量值的计算方法和数据处理中心差分计算误差修正量的方法,重点介绍了完好性监测算法以及执行监测(EXM)处理监测算法中所产生的报警标识的逻辑过程。2.针对SV19号卫星所出现的二阶阶跃信号异常模型导致定位精度下降的事件,本文将事件中的BPSK调制信号畸变模型扩展到BOC调制信号中,分别对BOC信号的数字畸变和模拟畸变模型进行分析研究,从时域和频域上得出BOC调制信号的数字畸变模型相关函数,从频域上得出模拟畸变模型相关函数。根据BOC信号相关峰对称性的特点设计出利用多对相关器对来对BOC调制信号的模拟畸变模型进行监测,提出利用直线拟合的方法对数字畸变模型进行监测。3.无论是突变的电离层风暴还是渐变的电离层斜坡模型对飞机的精密进场与安全着陆都有较大的影响,本文针对Shewhart监测算法不能监测较小的变化以及CUSUM监测算法不能一步监测较大变化的缺点,将Shewhart-CUSUM组合监测算法对电离层风暴进行监测,并利用实际参考接收机的电离层数据对组合算法的性能进行验证。4.针对卫星所广播的导航电文数据中可能存在的较大误差,通过利用新-旧星历比较检测法和历书-星历比较检测法来对新播发的卫星星历的有效性进行检测。根据多个月的正常卫星星历和历书数据计算出卫星位置,利用SPSS软件统计出推导2小时新-旧星历的卫星位置差和推导10小时历书-星历的卫星位置差,得出当前的新-旧星历比较检测法和历书-星历比较检测法的门限值。
[Abstract]:The positioning accuracy, continuity, completeness and availability of navigation system are the most important indexes in the performance of navigation service, which are paid more and more attention to by users. Among them, the performance requirement of integrity is the most difficult to satisfy the performance index of navigation service. In order to improve the performance of navigation system BOC signal modulation is introduced to improve the prediction accuracy of satellite ephemeris and carrier signals of multiple frequency bands are used in GNSS. In this context, in order to ensure the precise approach and safe landing of the aircraft, the ground-based enhancement system must solve many of the problems related to the propagation signal, the broadcast data and the measurement data. In this paper, the key technologies of the integrity monitoring of the foundation strengthening system are studied, the main contents are as follows: 1. Based on the precision approach landing of aircraft, the whole structure of the ground strengthening system is analyzed in this paper. This paper introduces the calculation method of the reference receiver using carrier phase measurement value to smooth the pseudo code measurement value and the method of difference calculation error correction in the data processing center. This paper mainly introduces the completion monitoring algorithm and the logical process. 2. 2. In this paper, the BPSK modulation signal distortion model in SV19 satellite is extended to the BOC modulation signal. The digital distortion model and analog distortion model of BOC signal are analyzed and studied respectively. The correlation function of digital distortion model of BOC modulation signal is obtained from time domain and frequency domain, and the correlation function of analog distortion model is obtained from frequency domain. According to the characteristic of correlation peak symmetry of BOC signal, a multi-pair correlator pair is designed to monitor the analog distortion model of BOC modulation signal, and the method of line fitting is proposed to monitor the digital distortion model. Whether it is a sudden ionospheric storm or a gradual ionospheric slope model, it has a great influence on the precise approach and safe landing of the aircraft. Aiming at the shortcoming that Shewhart monitoring algorithm can not monitor small changes and CUSUM monitoring algorithm can not monitor large changes in one step, the Shewhart-CUSUM combined monitoring algorithm is used to monitor ionospheric storms. The performance of the combined algorithm is verified by the ionospheric data of the actual reference receiver. In view of the possible errors in the satellite broadcast navigation message data, the validity of the newly transmitted satellite ephemeris is tested by using the new and old ephemeris comparison detection method and the almanac ephemeris comparison detection method. According to the normal satellite ephemeris and almanac data for many months, the satellite position is calculated, and the satellite position difference between the new and the old ephemeris for 2 hours and the satellite position difference for 10 hours for the new and old ephemeris are calculated by using the SPSS software. The threshold values of the new-old ephemeris comparison detection method and the ephemeris-ephemeris comparison detection method are obtained.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN967.1

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