BDSBAS-B1C服务性能评估模型分析

Analysis on BDSBAS-B1C service performance evaluation models

为了进一步提高卫星导航定位精度,提出一种北斗星基增强系统(BDSBAS)服务信号BDSBAS-B1C服务性能评估模型分析方法:介绍北斗三号全球卫星导航系统(BDS-3)星基增强和国外星基增强系统发展概况;并给出星基增强卫星轨道误差、钟差误差、电离层改正误差模型,以及完好性保护水平计算模型;然后基于国际GNSS监测与评估系统(iGMAS)数据对星基增强轨道、钟差、格网电离层改正精度以及定位服务性能进行评估,构建斯坦福(Stanford)图模型来判断系统定位结果的安全等级,并计算服务区内保护水平覆盖情况。实验结果表明,卫星轨道径向(R)、切向(T)、法向(N)方向改正精度分别为0.56、1.06、0.88 m,钟差改正精度为0.95 ns;水平、高程定位精度(95%)分别为1.31、2.06 m;水平、垂直保护水平(95%)分别为5.12、8.09 m,根据Stanford图安全等级结果,能够满足国际民航组织对一类垂直引导进近(APV-I)的指标要求。

In order to further improve the positioning accuracy of satellite navigation,the paper proposed an analysis method on BeiDou satellite based augmentation system(BDSBAS)-B1C service performance evaluation model:the development of BDSBAS and other satellite based augmentation system(SBAS)system was introduced,and the error correction and integrity calculation models of SBAS were given,including models of satellite orbit error,clock error,ionospheric correction and integrity protection level calculation;then,the orbit,clock error,grid ionospheric correction accuracy and positioning accuracy of SBAS were evaluated based on the iGMAS data;at the same time,the Stanford graph model was constructed to judge the security level of the system’s positioning results,and the protection level coverage in the service area was calculated finally.Experimental results showed that the satellite orbit correction accuracy in radial(R),tangent(T)and normal(N)directions would be 0.56,1.06 and 0.88 m,respectively,and the clock error correction accuracy would be 0.95 ns;meanwhile,the horizontal and elevation positioning accuracy(95%)would be 1.31 and 2.06 m,respectively,and the horizontal protection level and vertical protection level(95%)would be 5.12 and 8.09 m,respectively,which could fully meet the requirements of International Civil Aviation Organization(ICAO)for APV-I according to the safety level results of Stanford diagrams.