Investigating the effect of observation interval on GPS, GLONASS, Galileo and BeiDou static PPP

GNSS observation intervals can be tuned from low rate to high rates (such as 300 to 1 s) for the specific applications. In this study, the effect of sampling intervals of 1, 5, 15, and 30 s on the convergence time and positioning accuracy of static precise point positioning is investigated using high-rate data from 26 IGS (International GNSS Service)-MGEX (Multi-GNSS Experiment) stations over a three-week period in 2020. Six different GNSS constellations namely, GPS-only, GLONASS-only, Galileo-only, BeiDou-2-only, BeiDou-3-only, and multi-GNSS (GPS+GLONASS+Galileo+BeiDou-2+BeiDou-3) - are processed for static PPP. The results show that the use of higher rate of observation intervals significantly reduces the PPP convergence time for each GNSS constellation. Maximum improvements between 30 s and 1 s are found to be 55%, 60%, and 55% for north, east, and up components, respectively, for Galileo PPP. However, the results of positioning accuracy indicates that the use of higher rate of observation intervals slightly degrades the PPP converged positioning accuracy for each GNSS constellation except for BDS-3 and multi-GNSS PPP modes. The results demonstrate that the satellite clock interpolation error is mainly responsible for the degradation in accuracy at the higher rate of observation intervals compared with the orbit interpolation error.