Abstract
This study evaluates the readiness of the GNSS infrastructure at King Sejong Station (KSEJ), Antarctica, for integration into the International GNSS Service (IGS) network. Dual-epoch GNSS observations from 2009 and 2023 were reprocessed using the GAMIT/GLOBK 10.7 software suite in the ITRF2014 reference frame to assess long-term positional stability. The results show average annual horizontal velocities of 22 mm/yr toward the north-northeast, consistent with regional crustal motion driven by post-glacial rebound and tectonic processes. Signal quality analysis indicates a data availability of 99.37% and a cycle slip rate of 0.10%, both within IGS thresholds, although elevated multipath values were detected due to nearby infrastructure and limited azimuthal visibility, underscoring the need for site-specific mitigation. To ensure vertical reference consistency, geodetic leveling was conducted in 2023 to connect the tide gauge benchmark with nearby GNSS control points. A new temporary benchmark was installed following the loss of the original 2009 marker, enabling reliable vertical datum transfer and integration of tide gauge data with GNSS-derived heights. Overall, KSEJ meets most IGS requirements but requires infrastructural upgrades to address multipath interference, metadata automation, and data transmission reliability. These findings highlight the station's potential as a high-latitude geodetic reference site, contributing to global reference frame densification, sea level monitoring, and geodynamic studies in Antarctica.