Evaluation of GNSS timing performance based on circular T and analysis of system time offset

The paper first gives an analysis of timing service summary. With the development of multi-mode satellite navigation, it is expected that the evaluation of timing performance and monitoring of system time offset will be the research focus in the future. Through publication of BIPM Circular T the paper evaluates GNSS timing performance, and compared with GPS presents larger timing offset in GLONASS with the errors fluctuation around ± 10ns. Moreover, after modifying the receiver traceability data to UTC we analyze the errors of system time offset: different time precision in each navigation system may lead to greatly relative change in GNSS time offset.