• Journal of Positioning, Navigation, and Timing
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• v.13 no.4
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• pp.485-495
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• 2024

This study compares and analyzes CLAS correction messages received by an actual GNSS receiver with CLAS L6 data from the QZSS public archive. The Quasi-Zenith Satellite System (QZSS) broadcasts Centimeter Level Augmentation Service (CLAS) correction messages via the L6 band, providing correction information for satellite orbit, clock, code and phase biases, as well as ionospheric and tropospheric errors for GPS, Galileo, and the QZSS constellations. In this study, data collected from the Septentrio AsteRx4 GNSS receiver and the QZSS public archive from October to December 2023 were used for a comparative analysis, with a focus on the variations in the Message Generation Facility (MGF) ID, which indicates the institution generating the CLAS message, and their impact on correction values and positioning accuracy. The results showed that changes in the MGF ID led to variations in correction information, causing differences of about 1-2 cm in the PPP-RTK positioning results.