QZSS L6E增强服务改正数支持的PPP性能评估

准天顶卫星系统目前利用QZS-2~QZS-43颗卫星播发L6E信号,为东亚和大洋洲地区用户提供实时的增强服务。该文分析了L6E信号结构及轨道和钟差的计算模型,研究了目前L6E信号的覆盖范围和可用性,评估了L6E改正数恢复的卫星轨道和钟差及其用于动态PPP的精度水平。结果表明:我国用户在使用15°截止高度角时L6E信号仍有100%的可用性;L6E改正数恢复的GPS和GLONASS卫星轨道的3D RMS平均值分别为5.3和13.9 cm,卫星钟差的STD平均值分别为0.14和0.22 ns,利用GPS卫星的轨道和钟差进行的动态PPP可以获得水平优于10 cm、高程优于15 cm的精度,在加入GLONASS卫星后,东方向和高程方向定位误差和收敛时间均有明显改善。

Performance evaluation of precise point positioning aided by QZSS L6E augmentation service signal

The L6 E channel of the L6 signal in the latest quasi-zenith satellite system(QZSS)broadcasts the centimeter level augmentation service for experiment(CLAS-E)using QZS-2 to QZS-4 for users in East Asia and Oceanian region.The data format and the calculation algorithms for orbit and clock correction were introduced.Besides,the service area and availability were analyzed,moreover,the accuracy of orbit and clock recovered from L6 E signal and the corresponding precise point positioning were evaluated.The results showed that the availability was still up to 100%for the user in China with an elevation cut-off of 15°,the average 3 D RMS of orbit error was 5.3 and 13.9 cm for GPS and GLONASS respectively,and the average STD of clock error was 0.14 ns for GPS and 0.22 ns for GLONASS.The daily positioning accuracy of kinematic precise point positioning(PPP)could reach 10 cm in the horizontal component,15 cm in the height component when using GPS only,and the accuracy in the east and height component as well as the convergence time were dramatically improved when GLONASS was added.