GNSS辅助伪卫星系统定位初始值滤波算法与二阶数字滤波器设计

Initial Value Filtering Algorithm and Second-order Digital Filter Design for GNSS Assisted Pseudolite System Positioning

全球卫星导航系统(GNSS)辅助地基伪卫星定位的主要目的是解决工程实际应用中的一些问题。在地基伪卫星应用于码头港口等环境较为复杂的场景时,因为基站距离地面较近,多径现象较为严重,给固定整周模糊度带来了困难,无法得到准确的初始值。以GNSS与惯性导航系统组合定位模式为参考,对GNSS辅助伪卫星系统定位初始值的工作方案进行了研究,比较了算术平均值滤波、中值滤波等常用一阶数字滤波器的优缺点,并通过分析多组GNSS静态定位的误差,设计了一种二阶数字滤波器。试验结果表明,二阶滤波器的滤波效果达到了伪卫星初始值定位的精度要求,能够在工程上解决伪卫星的初始值问题。

The main purpose of global satellite navigation system(GNSS)assisted ground-based pseudo-satellite positioning is to solve some problems in practical engineering applications.When ground-based pseudo-satellites are used in more complex scenarios such as docks and ports,the base station is closer to the ground and the multipath phenomenon is more serious,which makes it difficult to fix the full-week ambiguity and cannot obtain accurate initial values.Taking the combined positioning mode of GNSS and inertial navigation system as a reference,the work plan of the initial positioning value of GNSS assisted pseudo-satellite system is studied,and the advantages and disadvantages of commonly used first-order digital filters such as arithmetic average filtering and median filtering are compared.By analyzing the error of static positioning of multiple groups of GNSS,a second-order digital filter is designed.The test results show that the filtering effect of the second-order filter meets the accuracy requirements of the pseudo-satellite initial value positioning,and can solve the pseudo-satellite initial value problem in engineering.