伪卫星增强北斗卫星导航系统定位技术研究

发布时间：2019-04-01 09:05

【摘要】：伪卫星具有抗干扰、灵活和低成本等诸多优点,已成为增强卫星导航系统或独立组网实现区域定位的有效工具,同时能够解决室内定位问题。近年来,对伪卫星的研究主要集中在伪卫星布局、提高几何精度因子和伪卫星设计等方面。文中以处于平流层的空基伪卫星增强北斗卫星导航系统为出发点,对增强的原理、伪距定位算法以及空基伪卫星的跟踪进行了研究,主要工作有以下三个方面： 1、当前北斗卫星导航系统存在着覆盖盲区,引入数量适当的伪卫星可以解决可见星数目少甚至没有可见星的问题。特别地,当北斗系统性能受到削弱时,可利用多颗伪卫星独立组网实现区域定位。引入伪卫星后,其位置误差相当于导航卫星的星历误差,对空基伪卫星而言,需通过跟踪以获取其准确的实时位置,才能削弱其位置误差对用户定位精度的影响。 2、针对空基伪卫星跟踪问题,文中在粒子滤波和交互多模型算法基础上提出了一种改进的多站观测交互多模型无迹粒子滤波算法。该算法以交互多模型算法为基本框架,采用改进的无迹粒子滤波作为模型匹配滤波器。仿真结果显示,改进后的算法对强机动、非线性模型的空基伪卫星跟踪取得了较高的精度。 3、通过跟踪空基伪卫星获得实时位置后,便可作为动态已知数参与定位方程组进行解算。针对用户定位问题,文中提出了一种基于最小二乘法和扩展卡尔曼滤波的混合定位算法。仿真表明,混合算法优于最小二乘法,定位精度得到了提高。
[Abstract]:Pseudo-satellite has many advantages, such as anti-jamming, flexibility and low cost. It has become an effective tool to enhance satellite navigation system or independent network to realize regional positioning, and it can solve indoor positioning problem at the same time. In recent years, the research on pseudo-satellite mainly focuses on pseudo-satellite layout, improving geometric accuracy factor and pseudo-satellite design. Based on the space-based pseudo-satellite enhanced Beidou satellite navigation system in the stratosphere, the principle of enhancement, the pseudo-range positioning algorithm and the tracking of space-based pseudo-satellite are studied in this paper. The main work is as follows: 1, At present, there is a blind area in Beidou satellite navigation system. The problem of fewer or no visible stars can be solved by introducing a proper number of pseudo-satellites. In particular, when the performance of Beidou system is weakened, multiple pseudosatellite independent networks can be used to realize regional positioning. With the introduction of pseudo-satellite, its position error is equivalent to the ephemeris error of navigation satellite. For space-based pseudo-satellite, it is necessary to obtain its accurate real-time position by tracking in order to weaken the influence of its position error on the positioning accuracy of users. 2. Aiming at the tracking problem of space-based pseudo-satellite, an improved multi-station observation-interaction multi-model unscented particle filter algorithm is proposed based on particle filtering and interactive multi-model algorithm. The algorithm takes the interactive multi-model algorithm as the basic framework and adopts the improved untraceable particle filter as the model matching filter. The simulation results show that the improved algorithm achieves high accuracy for space-based pseudo-satellite tracking with strong maneuvering and nonlinear model. 3, after tracking the real-time position of space-based pseudo-satellite, it can be used as a dynamic known number to participate in the positioning equations. In this paper, a hybrid localization algorithm based on least square method and extended Kalman filter is proposed to solve the problem of user localization. Simulation results show that the hybrid algorithm is superior to the least square method and the positioning accuracy is improved.
【学位授予单位】：西北大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：P228.4

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