Investigating Cycle Slip Repair for Single and Multi-Frequency Smartphone GNSS

Naman Agarwal and Kyle O’Keefe

Abstract:	Smartphone carrier-phase measurements are highly prone to cycle slips, degrading the performance of Precise Point Positioning (PPP) and Real-time Kinematics (RTK) on smartphones. This paper investigates the impact of cycle slip detection and repair (CSDR) across both single and dual-frequency undifferenced uncombined ionosphere-constrained PPP on smartphones. A cycle slip detection and repair (CSDR) methodology proposed in our earlier works is further investigated upon single and multifrequency smartphone GNSS data. Among five different ambiguity resolution techniques, a modified partial ambiguity resolution with fixed failure-rate ratio test (PAR-FFRT) method is identified to be the most effective for cycle slip repair and is integrated within the PPP framework. Extensive validation is conducted against high-quality IGS station data (using artificial slips) and four real-world static smartphone datasets spanning different handsets (Google Pixel 4, Pixel 7 Pro, Samsung Galaxy S20+ 5G) and environments, including open sky and urban conditions. Preliminary results are promising, showing improvement in PPP position convergence when cycle slips repair is performed, with the most substantial gains found in the vertical component, though benefits vary with slip density and signal redundancy. Despite promising findings, further validation on additional datasets and environments is required to establish the robustness and general efficacy of instant cycle slip repair compared to conventional ambiguity resetting. This study underscores the potential of advanced CSDR for enabling precise smartphone-based GNSS applications.
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:	2550 - 2565
Cite this article:	Agarwal, Naman, O’Keefe, Kyle, "Investigating Cycle Slip Repair for Single and Multi-Frequency Smartphone GNSS," Proceedings of the 38th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2025), Baltimore, Maryland, September 2025, pp. 2550-2565. https://doi.org/10.33012/2025.20340
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