北斗系统对流层延迟改正模型精度分析

Accuracy Analysis of Tropospheric Delay Correction Model for Beidou Satellite Navigation System

北斗系统是我国自主研制的卫星导航定位系统,为提高该系统的定位精度,必须对其误差源引起的定位误差进行修正。对流层延迟是影响北斗卫星定位精度的误差源之一,它是由对流层大气对卫星信号的折射而引起,因此需要进行对流层延迟改正,其改正精度将直接影响卫星的定位精度。针对目前导航系统常用的3种对流层延迟模型,利用公认的电波射线描迹法进行比对,得到了各个模型的特征和适用范围,从而为我国北斗导航卫星定位应用中的对流层延迟模型选择奠定基础。

Beidou system is a satellite navigation and positioning system developed independently by China.In order to improve the positioning accuracy of the system,the positioning error caused by the error sources must be corrected.The tropospheric delay is an error source affecting the positioning accuracy of the Beidou satellite,which is caused by the refraction of satellite signals in the tropospheric atmosphere.Therefore,the tropospheric delay correction is needed.The correction accuracy will directly affect the positioning accuracy of the satellite.In this paper,a comparison is made among the three kinds of commonly used tropospheric delay models in current navigation system by use of the known radio ray tracing method.The characteristics and applicable range of each model are obtained,which lays the foundation for the selection of tropospheric delay model in Beidou navigation satellite positioning application.