Along with the rapid development of GNSS, not only BeiDou, but also Galileo, and the newly launched GPS satellites can provide signals on three frequencies at present. To fully take advantage of the multi-frequency multi-system GNSS observations on precise point positioning (PPP) technology, this study aims to implement the triple-frequency ambiguity resolution (AR) for GPS, Galileo, and BeiDou-2 combined PPP using the raw observation model. The processing of inter-frequency clock bias (IFCB) estimation and correction in the context of triple-frequency PPP AR has been addressed, with which the triple-frequency uncalibrated phase delay (UPD) estimation is realized for real GPS observations for the first time. In addition, the GPS extra-wide-line UPD quality is significantly improved with the IFCB correction. Because of not being contaminated by the IFCB, the raw UPD estimation method is directly employed for Galileo which currently has 24 satellites in operation. An interesting phenomenon is found that all Galileo satellites except E24 have a zero extra-wide-lane UPD value. With the multi-GNSS observations provided by MGEX covering 15 days, the positioning solutions of GPS + Galileo + BeiDou triple-frequency PPP AR have been conducted and analyzed. The triple-frequency kinematic GNSS PPP AR can achieve an averaged 3D positioning error of 2.2 cm, and an averaged convergence time of 10.8 min. The average convergence time can be reduced by triple-frequency GNSS PPP AR by 15.6% compared with dual-frequency GNSS PPP AR, respectively. However, the additional third frequency has only a marginal contribution to positioning accuracy after convergence.

中文翻译：

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GPS + Galileo +北斗精确定位，具有三频模糊度分辨率

随着GNSS的飞速发展，目前北斗，伽利略和新发射的GPS卫星都可以提供三个频率的信号。为了充分利用多频多系统GNSS对精确点定位（PPP）技术的观测，本研究旨在使用GPS实现GPS，伽利略和北斗2组合PPP的三频模糊度解决方案（AR）。原始观测模型。已经解决了在三频PPP AR环境中进行跨频时钟偏差（IFCB）估计和校正的过程，首次实现了针对真实GPS观测的三频未校准相位延迟（UPD）估计。此外，借助IFCB校正，GPS超宽线UPD质量得到了显着改善。由于不受IFCB的污染，UPD原始估算方法直接用于伽利略（Galileo），目前有24颗正在运行的卫星。发现一个有趣的现象，除E24之外，所有伽利略卫星的超宽车道UPD值均为零。利用MGEX提供的15天多GNSS观测资料，对GPS + Galileo +北斗三频PPP AR的定位方案进行了分析。三频运动学GNSS PPP AR可以实现平均3D定位误差为2.2厘米，平均收敛时间为10.8分钟。与双频GNSS PPP AR相比，三频GNSS PPP AR的平均收敛时间可减少15.6％。然而，附加的第三频率在收敛之后仅对定位精度有边际贡献。UPD原始估算方法直接用于伽利略（Galileo），该伽利略目前有24颗正在运行的卫星。发现一个有趣的现象，除E24之外，所有伽利略卫星的超宽车道UPD值均为零。利用MGEX提供的15天多GNSS观测资料，对GPS + Galileo +北斗三频PPP AR的定位方案进行了分析。三频运动学GNSS PPP AR可以实现平均3D定位误差为2.2厘米，平均收敛时间为10.8分钟。与双频GNSS PPP AR相比，三频GNSS PPP AR的平均收敛时间可减少15.6％。然而，附加的第三频率在收敛之后仅对定位精度有边际贡献。UPD原始估算方法直接用于伽利略（Galileo），目前有24颗卫星在运行。发现一个有趣的现象，除E24之外，所有伽利略卫星的超宽车道UPD值均为零。利用MGEX提供的15天多GNSS观测资料，对GPS + Galileo +北斗三频PPP AR的定位方案进行了分析。三频运动学GNSS PPP AR可以实现平均3D定位误差为2.2厘米，平均收敛时间为10.8分钟。与双频GNSS PPP AR相比，三频GNSS PPP AR的平均收敛时间可减少15.6％。然而，附加的第三频率在收敛之后仅对定位精度有边际贡献。