WAAS系统中电离层折射校正的新方法及计算结果

电离层介质的色散性是影响电磁波信号进行卫星导航定位精度的重要因素之一.配合北斗二代分系统研制任务,提出了一种新的电离层折射校正算法,并利用2000年7月1日到3日的双频GPS观测数据对6个用户站进行试算,进一步将试算所得均方根误差和电离层网格算法得到的误差进行比较.结果表明,对于中纬区域的用户站,估算的TEC误差约为0.5 m左右;而低纬用户误差相对增大,为1 m左右.文中给出的算法与电离层网格模型所提供的精度相差不多,在未来中国自主的卫星增强系统中采用新方法进行电离层进行修正是可行的及有效的.

New Algorithm and Results of WAAS Ionospheric Delay Correction

Ionospheric delay resulted from radio signals traveling in ionosphere is the largest source of errors for satellite-based positioning and navigation system. A new algorithm of ionospheric delay correction was proposed in the course of taking the task of "BD-2" subsystem, and tested using 6 dual-frequency GPS stations' observational data of China crust deformation monitoring network. Further, comparison of TEC (Total Electron Content) errors derived from the proposed algorithm to the ones from ionospheric grid algorithm was considered. The results show that the gauged error of TEC is about 0.5 meter for the users located in middle latitude, but the error increases and reaches one meter for the low latitude users. The proposed method and ionospheric grid model can provide almost performance for the view of ionospheric delay correction. It is concluded that the proposed method is valid and practicable for the future satellite-based augmentation system of China.