Research Information System
Arabian Journal of Geosciences, vol.14, no.13, 2021 (SCI-Expanded)
© 2021, Saudi Society for Geosciences.PPP, which is currently challenging in the GNSS positioning, may become the precise GNSS positioning mode in the future. Therefore, its positional accuracy and convergence time should be assessed fully. To investigate the positional accuracy and the convergence time of PPP, firstly seven daily GPS data from October 2, 2016, to October 8, 2016 at KUWT permanent GNSS station in Kuwait are processed by the BPE-PPP software as well as three online web-based post processing PPP services (the APPS, the CSRS-PPP, and the Trimble RTX). Comparisons of the PPP estimated daily coordinates with the ITRF08 coordinates at the KUWT station result in centimeter level three-dimensional positional accuracy, while the PPP estimated daily coordinates are found to be biased in varying size to the ITRF08 coordinates. The hourly GPS sessions of 2 h, 4 h, 6 h, 8 h, 12 h and 24 h on October 5, 2016 at the KUWT station are processed by using these four PPP software. The estimated hourly session coordinates are compared with the BPE-PPP combined coordinates of the seven BPE-PPP daily solutions. The comparisons reveal that positional accuracy better than 2 cm with convergence time after 2 h can be obtained in static mode. The best positional accuracy and the convergence time are obtained by the APPS web-based online PPP service. Moreover, the empirical GPS PPP accuracy formulas are evaluated and found to be optimistic.