为了分析当前GPS(Global Positioning System)、Galileo(Galileo Navigation Satellite System)和BDS-3(Beidou Navigation Satellite System with Global Coverage)广播星历的精度,详细分析研究了各种偏差改正及消除方法,并尽可能地消...为了分析当前GPS(Global Positioning System)、Galileo(Galileo Navigation Satellite System)和BDS-3(Beidou Navigation Satellite System with Global Coverage)广播星历的精度,详细分析研究了各种偏差改正及消除方法,并尽可能地消除了系统误差和粗差对评估结果的影响。选取2021-11-01/12-31共61天MGEX(multi-GNSS experiment)发布的多系统混合广播星历与武汉大学分析中心发布的事后精密星历数据进行实验,对GPS、Galileo和BDS-3近期广播星历精度进行对比分析,实验结果表明:3个系统广播星历整体精度由高到低依次是Galileo、BDS-3和GPS,其空间信号测距误差的RMS(root mean square)分别优于0.17、0.25和0.37 m,整体轨道精度的RMS分别优于0.17、0.12和0.25 m,BDS-3广播星历的轨道精度最高,钟差误差的RMS分别优于0.15、0.23和0.27 m,Galileo广播星历的钟差精度最高。对于GPS卫星的广播星历,blockⅢA卫星钟差和轨道精度均优于其他GPS类型卫星。展开更多
Real-time precise point positioning (PPP) is possible through the use of real-time precise satellite orbit and clock corrections, which are available through a number of organizations including the International GNSS ...Real-time precise point positioning (PPP) is possible through the use of real-time precise satellite orbit and clock corrections, which are available through a number of organizations including the International GNSS Service (IGS) real-time service (IGS-RTS). Unfortunately, IGS-RTS is only available for the GPS and GLONASS constellations. In 2018, a new real-time service, NAVCAST, which provides real-time precise orbit and clock corrections for the GPS and Galileo constellations, was launched. In this research, the potential performance of real-time PPP which makes use of NAVCAST real-time corrections is analyzed using various static and kinematic datasets. In the static dataset, 24 hours of observations from eight IGS stations in Canada over three different days were utilized. The static results show that the contribution of Galileo satellites can improve the positioning accuracy, with 30%, 34%, and 31% in east, north, and up directions compared to the GPS-only counterparts. In addition, centimeter-level positioning accuracy in the horizontal direction and decimeter-level positioning accuracy in the vertical direction can be achieved by adding Galileo observations. In the kinematic dataset, a real vehicular test was conducted in urban and suburban combined areas. The real-time kinematic GPS/Galileo PPP solutions demonstrate an improvement of about 53%, 45%, and 70% in east, north, and up directions compared to the GPS-only counterparts. It is shown that the real-time GPS/Galileo PPP can achieve a sub-decimeter horizontal positioning accuracy and about meter-level vertical positioning accuracy through the use of NAVCAST real-time corrections.展开更多
文摘为了分析当前GPS(Global Positioning System)、Galileo(Galileo Navigation Satellite System)和BDS-3(Beidou Navigation Satellite System with Global Coverage)广播星历的精度,详细分析研究了各种偏差改正及消除方法,并尽可能地消除了系统误差和粗差对评估结果的影响。选取2021-11-01/12-31共61天MGEX(multi-GNSS experiment)发布的多系统混合广播星历与武汉大学分析中心发布的事后精密星历数据进行实验,对GPS、Galileo和BDS-3近期广播星历精度进行对比分析,实验结果表明:3个系统广播星历整体精度由高到低依次是Galileo、BDS-3和GPS,其空间信号测距误差的RMS(root mean square)分别优于0.17、0.25和0.37 m,整体轨道精度的RMS分别优于0.17、0.12和0.25 m,BDS-3广播星历的轨道精度最高,钟差误差的RMS分别优于0.15、0.23和0.27 m,Galileo广播星历的钟差精度最高。对于GPS卫星的广播星历,blockⅢA卫星钟差和轨道精度均优于其他GPS类型卫星。
文摘Real-time precise point positioning (PPP) is possible through the use of real-time precise satellite orbit and clock corrections, which are available through a number of organizations including the International GNSS Service (IGS) real-time service (IGS-RTS). Unfortunately, IGS-RTS is only available for the GPS and GLONASS constellations. In 2018, a new real-time service, NAVCAST, which provides real-time precise orbit and clock corrections for the GPS and Galileo constellations, was launched. In this research, the potential performance of real-time PPP which makes use of NAVCAST real-time corrections is analyzed using various static and kinematic datasets. In the static dataset, 24 hours of observations from eight IGS stations in Canada over three different days were utilized. The static results show that the contribution of Galileo satellites can improve the positioning accuracy, with 30%, 34%, and 31% in east, north, and up directions compared to the GPS-only counterparts. In addition, centimeter-level positioning accuracy in the horizontal direction and decimeter-level positioning accuracy in the vertical direction can be achieved by adding Galileo observations. In the kinematic dataset, a real vehicular test was conducted in urban and suburban combined areas. The real-time kinematic GPS/Galileo PPP solutions demonstrate an improvement of about 53%, 45%, and 70% in east, north, and up directions compared to the GPS-only counterparts. It is shown that the real-time GPS/Galileo PPP can achieve a sub-decimeter horizontal positioning accuracy and about meter-level vertical positioning accuracy through the use of NAVCAST real-time corrections.
