Precise point positioning with ambiguity resolution (PPP-AR) provides globally available centimeter-level positioning, but its convergence time remains a limiting factor for time-critical applications. One important contributor to slow convergence is short-term mismodeling of the zenith wet delay (ZWD), which affects the float ambiguity estimates and delays integer fixing. Numerical weather models (NWMs) offer physically reali...

Un-differenced (UD) ambiguity resolution (AR) is widely applied since it can avoid wrong-fixing and fix the most of ambiguities. However, in the precise orbit determination (POD) solution using ground network only, the accuracy of float estimates is not sufficient for a direct UD AR, and thus double-differenced (DD) AR must be conducted first. It is demonstrated that integrating low-Earth orbit (LEO) satellites improves the ac...

High-precision Global Navigation Satellite Systems (GNSS) orbits are critical for real-time clock estimation and precise positioning service; however, the prediction error grows gradually with the increasing prediction session. In this study, we present a new efficient precise orbit determination (POD) strategy referred to as the epoch-parallel processing to reduce the orbit update latency, in which a 24-h processing job is sp...

Global Navigation Satellite Systems (GNSS) Real-time Precise Point Positioning (RT-PPP) strongly relies on the precise satellite orbits and clocks, especially the latter requires high update rate, e.g., five seconds, due to its limited prediction accuracy. Such a high-rate update frequency is a burden to both the data analysis and communicating, and interruption in communicating is almost unavoidable. For the new constellation...