不同电离层映射函数对导航精度的影响分析

The effects on navigation precision:an ionospheric mapping function perspective

介绍广播星历映射函数、投影映射函数、几何映射函数和椭球映射函数4种不同的电离层映射函数,基于Klobuchar电离层模型分析不同电离层映射函数对导航精度的影响。结果表明,不同电离层映射函数对导航精度的影响在厘米级到分米级;在不同太阳活动期,椭球映射函数和几何映射函数对导航精度影响基本相同;在太阳活动活跃期,导航精度由高到低依次为几何映射函数、投影映射函数、广播星历映射函数;在太阳活动平稳期,导航精度由高到低依次为广播星历映射函数、投影映射函数、几何映射函数。建议在导航定位中,电离层映射函数在太阳活动活跃期时采用几何映射函数,在太阳活动低谷期时采用广播星历映射函数。

This paper introduces four different ionospheric mapping functions,including broadcast ephemeris mapping function,projection mapping function,geometric mapping function and ellipsoid mapping function,and compares their effects on navigation precision based on Klobuchar ionosphere model.The results show that the effect on navigation precision varies from centimeter-level to decimeterlevel when different ionospheric mapping functions are utilized.In all solar period,the navigation precision is fundamentally same when geometric mapping function and ellipsoid mapping function are utilized.In the active solar activity,geometric mapping function is superior to projection mapping function,and projection mapping function is better than broadcast ephemeris mapping function in navigation precision.However,in the trough solar activity,broadcast ephemeris mapping function is the best one when being used in navigation and positioning,and projection mapping function is between broadcast ephemeris mapping function and geometric mapping function in a navigation precision perspective.Therefore,geometric mapping function is advised to be utilized during the active solar activity,while broadcast ephemeris mapping function is advised during the trough solar activity.