基于iGMAS的BDS空间信号精度性能评估

Accuracy Evaluation of BDS Spatial Signal based on iGMAS

全球连续监测评估系统(international GNSS Monitoring&Assessment System,iGMAS)是我国为了向导航用户提供安全可靠的全球卫星导航系统(Global Navigation Satellite System,GNSS)服务而搭建的对导航性能指标进行监测和评估的平台。在卫星导航系统中,空间信号精度的优劣直接决定卫星导航的定位精度,因此对空间信号精度的评估十分必要。此次研究基于iGMAS提供的广播星历和精密星历产品,通过分段法求得用户测距误差,然后使用差分法分别求得用户测速误差和用户加速度误差。实验结果表明,用户测距误差、用户测速误差、用户加速度误差均达到国际精度(95%置信度),iGMAS下的广播星历数据可作为评估空间信号的数据来源;我国的iGMAS已经较为成熟,可作为评估空间信号精度的平台。

iGMAS （International GNSS Monitoring and Assessment System） built up in China is a monitoring and evaluation platform for navigation performance indicators and provides navigation users with safe and reliable GNSS （Global Navigation Satellite System） services. In satellite navigation systems, the accuracy of spatial signal directly determines the positioning accuracy of satellite navigation, so the evaluation of spatial signal accuracy is necessary. The research is focused on the broadcast ephemeris and precision ephemeris products provided by iGMAS, and the user＇s ranging error is acquired by the segmentation method, and then the user＇s speed-measurement error and user acceleration error respectively obtained by the difference method. The experimental results indicate that the accuracy of BDS evaluation, involving user ranging error, user speed-measurement error, and user acceleration error, reaches the international accuracy （of 95% confidence）, and broadcast ephemeris data under iGMAS can be used as a data source for evaluating spatial signals. China＇s iGMAS is fairly mature and can be used as a platform for evaluating the accuracy of spatial signals.