GNSS UTCO参数演变分析与对比评估北大核心CSCD

全球导航卫星系统(GNSS)发播的协调世界时偏差参数(UTCO)随着导航系统现代化升级而更新,尤其是GPS和BDS的UTCO参数具有明显变化。从模型上看,一阶溯源模型改为二阶溯源模型,兼容一阶模型;从分辨率上看,参数分辨率普遍变小,从而提高对UTCO微小变化的敏感性。通过研究GPS、BDS、Galileo、GLONASS四大导航系统GPS LNAV电文、GPS CNAV电文、BDS D1/D2电文、BDS B-CNAV电文、Galileo电文、GLONASS电文中的UTCO参数,基于国际计量局(BIPM)国际时间公报(T公报)UTCr-UTC(k)数据,将GNSS UTCO参数统一到快速协调世界时(UTCr),分析不同系统发播的UTCO参数性能。同时以国家授时中心(NTSC)监测的GNSS系统时差和BIPM快速T公报作为参考,评估GNSS系统发播的协调世界时偏差误差(UTCOE)。结果表明,在实验时段内,GPS CNAV电文的UTCO参数性能优于GPS LNAV电文,BDS B-CNAV电文的UTCO参数性能优于BDS D1/D2电文;GPS、Galileo的UTCO参数性能优于BDS、GLONASS,BDS和GLONASS在UTC溯源中具有一定的系统误差。

Evolution Analysis and Comparative Evaluation of GNSS UTCO Parameter

The coordinated universal time offset(UTCO) parameter broadcast by the global navigation satellite system(GNSS) is updated with the modernization upgrading navigation systems. In particular, the UTCO parameters for GPS and BDS have been significantly changed. From the perspective of model, the first-order traceability model has been replaced with a second-order traceability model, compatible with the first-order model. From the perspective of resolution, the parameter resolution has generally decreased, improving sensitivity to small changes in UTCO. By investigating the UTCO parameters in the GPS LNAV messages, GPS CNAV messages, BDS D1/D2 messages, BDS B-CNAV messages, Galileo messages and GLONASS messages of the four major navigation systems GPS, BDS, Galileo and GLONASS, and based on the UTCr-UTC(k) data published by international bureau of measurement(BIPM), we integrate the GNSS UTCO parameters into the fast coordinated universal time(UTCr) to analyze the performance of UTCO parameters broadcast by various systems. Meanwhile, we adopt the time offset of GNSS system monitored by the national time service center(NTSC) and the circular T bulletin published by BIPM as references to evaluate the coordinated universal time offset error(UTCOE) of GNSS system. The results show that the UTCO parameters of GPS CNAV messages perform better than GPS LNAV messages, and the UTCO parameters of BDS B-CNAV messages perform better than BDS D1/D2 messages within the experimental period. The UTCO parameters of GPS and Galileo perform better than BDS and GLONASS, and BDS and GLONASS had some systematic errors in the UTC traceability.