Stability analysis of continuous operating reference stations on Vancouver Island with a permanent GPS deformation array based on GAMIT/GLOBK

Continuous operating reference station (CORS) networks, underpinned by GNSS technology, support various technological services including comprehensive surveying, navigation, and remote sensing. The stability of these CORS networks is crucial for maintaining the high accuracy and reliability of data services. In this paper, we focus on analyzing the GPS deformation array of Vancouver Island, Canada, and present a thorough stability analysis scheme for CORS networks that is adaptable to other areas with frequent tectonic activity. For this study, we first conducted a data quality assessment based on three primary indices — namely, multipath effect on L1 and L2 frequency, signal-to-noise ratio in both frequency and cycle slip ratio — using the Transfer Edit Quality Check (TEQC) software. Then, we achieved high-precision data processing using the GAMIT/GLOBK software, in order to quantify the changes at each station over the specific periods. Seasonality analysis was also incorporated into the pipeline. Considering the potential variances affecting the deformation array over time, the coordinates were transformed under a unified reference frame, enabling the study of changes with station coordinates from different epochs under the same systematic conditions. Additionally, the impact of plate tectonic was examined through correlation analysis. The results showed that, while the observation data from the QUAD station in the island deformation array are of poor quality, relative stability was maintained within the deformation array. The PTRF and CLRS stations exhibited vertical instability in the fall season, while the QUAD station showed a weaker instability trend. The remaining stations maintained good stability with closer stations demonstrating stronger consistency in their displacement. In terms of plate tectonic, the deformation array stations exhibit a similar southwestward displacement trend as the North American Plate in the horizontal direction, but no significant trend in the vertical direction. • A comprehensive CORS network stability analysis scheme is presented. • Station offset rates are accurately fitted with an inverse distance weighting method. • The correlation analysis between CORS station offsets and plate drifts is conducted.