多模GNSS PPP时间传递性能比对分析

精密单点定位(PPP)时间传递技术是国际时间比对的重要手段之一，为协调世界时的计算做出巨大贡献。为探究多系统融合PPP时间频率传递性能，选取3个国际授时实验室的测站数据组成2条链路，采用8种实验模式对比分析单系统、双系统、三系统和四系统PPP时间频率传递性能。实验结果表明：各多系统组合较单GPS系统在可见星数上均有较大提升，且极大改善了钟差精度因子，增加了时间比对结果的稳健性和可靠性。在时间传递稳定性方面：对于453.4 km的PTBB-BRUX链路，较单GPS系统，双系统中GPS/BDS组合提升效果最优，提升率约为10.39%,三系统中GPS/GLONASS/BDS组合提升率最优，约为11.86%,四系统组合提升率为11.98%,可从0.046 7 ns提升至0.041 1 ns;对于8 031.8 km的PTBB-NIST链路，GPS/BDS组合提升率约为4.89%,GPS/GLONASS/BDS组合提升率约为5.49%,四系统组合提升率为5.79%,可从0.114 0 ns提升至0.107 4 ns。在频率传递稳定度方面：在前10 000 s内双系统组合平均提升17.6%,三系统...

Comparative analysis of multi-GNSS PPP time transfer performance

Precise point positioning (PPP) time transfer technology is one of the important means of international time comparison and has made great contribution to the calculation of coordinated universal time (UTC). In order to investigate the performance of multi-system PPP time and frequency transfers, the station data from three international timing laboratories are selected to form two links, and eight experimental modes are used to compare and analyze the performance of single system, dual system, triple system and quadruple system PPP time and frequency transfers. The experimental results show that each multi-system combination has a greater improvement in the number of visible satellites than the single GPS system, and greatly improves the time dilution of precision (TDOP), which increases the robustness and reliability of the time comparison results. In terms of time transfer stability, for the PTBB-BRUX time link with a geodetic distance of 453.4 km, compared with the single GPS system, the GPS/BDS combination in the dual system has an excellent enhancement effect, with an enhancement rate of about 10.39%, the GPS/GLONASS/BDS combination in the triple system has an optimal enhancement rate of about 11.86%, and the quadruple system has an enhancement rate of 11.98%, which can be improved from 0.046 7 ns to 0.041 1 ns; for the PTBB-NIST time link with a geodetic distance of 8 031.8 km, the GPS/BDS combination enhancement rate is about 4.89%, the GPS/GLONASS/BDS combination enhancement rate is about 5.49%, and the quadruple system combination enhancement rate is 5.79%, which can be improved from 0.114 0 ns to 0.107 4 ns. In terms of frequency transfer stability, the average improvement within the first 10 000 s is 17.6% for dual system combinations, 20.5% for triple system combinations, and 21.6% for quadruple system combinations.