A Consideration on Method to Improve the Convergence Speed of MADOCA-PPP in GNSS Positioning

Hirotaka Kuwabara, Koshiro Achioku, and Yukihiro Kubo

Peer Reviewed

Abstract:	GNSS is used in a wide variety of applications including autonomous vehicle operation, UAV navigation and so on. And with that, its positioning accuracy requirements are becoming increasingly demanding. The methods of GNSS positioning are relative positioning, single point positioning and precise point positioning (PPP), and we use PPP in this study. PPP can estimate the position using a single receiver with high accuracy by using the correction information, or estimating error factors. MADOCA-PPP is a service that broadcasts correction information which is satellite clock errors, satellite orbit errors and satellite signal bias from Japanese Quasi-Zenith Satellite System (QZSS)“ Michibiki ”and PPP method utilizing this information. We can estimate high accuracy position using MADOCA-PPP. However, since ionospheric delay and tropospheric delay correction information are not included in MADOCA-PPP, we have to estimate these error factors on the receiver side. Due to the time-consuming nature of estimating these errors, convergence of the estimated position using MADOCA-PPP takes a long time. Therefore, in this study, in the precise point positioning using MADOCA-PPP, the receiver position, receiver clock error, and tropospheric delay with a certain degree of accuracy are obtained by using“ Ionospheric-free linear combination” as step 1, and step 2 is that the Kalman filter is applied by using them as the initial value of the state vector, and the method to improve the convergence is examined.
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:	2055 - 2068
Cite this article:	Kuwabara, Hirotaka, Achioku, Koshiro, Kubo, Yukihiro, "A Consideration on Method to Improve the Convergence Speed of MADOCA-PPP in GNSS Positioning," Proceedings of the 38th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2025), Baltimore, Maryland, September 2025, pp. 2055-2068. https://doi.org/10.33012/2025.20249
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