• 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.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.9
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• pp.1730-1740
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• 2016

This paper introduces a guest identity provider system for eduroam which is a global Wi-Fi service targeting users enrolled in higher education and research institutions. Developed eduroam AND (AutheNtication Delegation) system enables users to create their eduroam user accounts and to access eduroam regardless of their locations. Users with no organizational eduroam account therefore can freely access eduroam using the system. A federated authentication model is implemented in the system, and thus the system has merits of having high accessibility, indirectly verifying users and organizations possible, saving management overhead. Status monitoring is essential because authentication request and response messages are routed by eduroam network. eduroam AND performs active monitoring to check service availability and visualizes the results, which increases operational and management efficiency. We leveraged open-source libraries to implement eduroam AND and run the system on KREONET (Korea REsearch Open NETwork). Lastly, we present implementation details and qualitively evaluate the system.