An Advanced PPP/PPP-RTK Software Package Designed for Urban Navigation Based on RTKLIB

Cheng-Wei Wang and Shau-Shiun Jan

Abstract:	Urban positioning poses a formidable challenge, even with promising techniques such as precise point positioning (PPP) or precise point positioning real-time kinematic (PPP-RTK). Although PPP/PPP-RTK can provide decimeter-level accuracy when satellite ephemeris dominates satellite-specific errors (including satellite position, clock bias, and code bias), the benefits of carrier phase measurements are often considerably diminished in urban areas. This limitation is primarily due to severe multipath effects and non-line-of-sight (NLOS) conditions, which significantly degrade positioning performance. This paper presents preliminary results based on the dense urban dataset, TEX-CUP. To address the long convergence time typically associated with PPP, a single-station augmented PPP-RTK approach is proposed. This method is used to generate state-space representation atmospheric data, including constraints of ionospheric and tropospheric delay. In addition, several techniques for fault detection and exclusion, and robust error models based on the extended Kalman filter, are proposed in this paper. Overall, the robust error model yields better performance, achieving a horizontal error of 1.70 meters and a maximum horizontal error of 28.56 meters. Finally, a first result of PPP-RTK based on factor graph optimization is presented, demonstrating the best performance with a horizontal positioning error of 0.46 meters and a maximum horizontal error of 1.21 meters. The code is open-sourced and available at the following link: https://github.com/MayHarryWang/Urban-RTKLIB
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:	1415 - 1426
Cite this article:	Wang, Cheng-Wei, Jan, Shau-Shiun, "An Advanced PPP/PPP-RTK Software Package Designed for Urban Navigation Based on RTKLIB," Proceedings of the 38th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2025), Baltimore, Maryland, September 2025, pp. 1415-1426. https://doi.org/10.33012/2025.20443
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