Assessment of PPP-AR Based on IF Model Generalized to all Available Frequencies

Anthony Hoareau, Patrick Sarri, Khoder Makkawi, Jessica Colombel, Remi Burtin, Alexis Guinamard

Abstract:	Most of the papers on Precise Point Positioning (PPP) with phase ambiguity resolution (AR) are based on the undifferentiated and uncombined (UDUC) method that proved interesting advantages in terms of computational simplicity and convergence times in multi-frequency context. Ionosphere-free (IF) methods remain a good traditional alternative but suffer from a dual frequency (DF) operation (triple frequency (TF) in most advanced iono-free PPP algorithms), which does not allow best convergence time when much more are available for Galileo and BeiDou constellations. In this paper, we assess the performance of a patented PPP-AR algorithm based on the IF method but generalized to all available frequencies for GPS, Galileo and BeiDou constellations in both static and kinematic acquisitions. For static tests, compared to dual-frequency PPP (DF-IF), the 95th percentile of vertical and horizontal error distributions is reduced by 81 %, while the reduction reaches approximately 66 % for kinematic data. The fix rate is improved by 31 % and 53 % in static and kinematic modes, respectively. In both cases, the convergence time is around 20 seconds, representing an improvement of 80 %. Furthermore, when compared to triple-frequency PPP (TF-IF), multi-frequency PPP (MF-IF) shows gains of 44 % and 32 % in convergence time for static and kinematic scenarios, respectively. The 95th percentile of horizontal errors is also reduced by 57 % in static and 30 % in kinematic conditions. The proposed multi-frequency ionosphere-free algorithm achieves significantly faster convergence and enhanced robustness, offering performance comparable to the UDUC method without relying on first-order ionospheric corrections or estimations. It effectively mitigates ionospheric effects while preserving the benefits of multi-constellation and multi-frequency observations.
Published in:	Proceedings of the 38th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2025) September 8 - 12, 2025 Hilton Baltimore Inner Harbor Baltimore, Maryland
Pages:	2524 - 2535
Cite this article:	Hoareau, Anthony, Sarri, Patrick, Makkawi, Khoder, Colombel, Jessica, Burtin, Remi, Guinamard, Alexis, "Assessment of PPP-AR Based on IF Model Generalized to all Available Frequencies," Proceedings of the 38th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2025), Baltimore, Maryland, September 2025, pp. 2524-2535. https://doi.org/10.33012/2025.20338
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