英文摘要 |
The e-GNSS real-time kinematic positioning system (e-GNSS for short) provides the real-time RTK service with 2 cm precision and has been used for geospatial data collection. The e-GNSS updates the CORS coordinates regularly to keep the interrelationship because of the surface displacement in Taiwan. The 6.2 magnitude earthquake made several residential buildings either collapsed or tilted on 6 Feb, 2018 at 11:50 PM, and the biggest displacement is about 45 cm (HUAL). National Land Surveying and Mapping Center (NLSC) updated 11 CORS' coordinates, 53 basic control points and the transformation model after detecting and recalculating the displacement. The results show the horizontal precision is less than 5 cm, and the vertical precision is less than 10 cm. By this experience, after a severe earthquake, it is necessary that NLSC recalculate the system coordinates and the transformation model to keep the service in accurate precision. Meanwhile, NLSC also should examine the precision of basic control points in the region to ensure the precision fits surveying work. |