An Assessment Method for Signal-In-Space Continuity of BDS Satellites Based on Reliability Theory

When satellite navigation systems provide services, the users are both system users and system testers. Assessing and verifying the signal-in-space (SIS) performance of BeiDou satellites can provide a certain reference basis for performance improvement and global construction of BeiDou navigation satellite system (BDS). Based on reliability theory, a SIS continuity performance assessment model for BDS satellites has been established in this paper. And then, various unscheduled outages have been detected from 2019 BDS satellite broadcast ephemeris data by using post event precise ephemeris comparison method to assess BDS SIS continuity. The assessment results indicate that, except for some newly launched and nearly retired BDS satellites, the SIS continuity of all other BDS satellites can meet the continuity performance standards provided by BDS-OS-PS-2.0.