부산대학교 도서관

Taiwan is located at the plate boundary between the Eurasian plate and Philippine Sea plate. Due to the relative motions between the two plates, the accuracy of the current static geodetic datum TWD97[2010] are decreasing with time. From July 2018 to Sep. 2019, the GNSS observations from 2,354 control points, 432 continuously operating reference stations (CORS) and also 6 IGS stations were collected by National Land Surveying and Mapping Center (NLSC), consisting of 535 sessions and 79,419 baselines. First, by means of the minimum constrained on KMNM site network adjustment, 3,153 baselines were eliminated and 79,419 were used. The average accuracy are ±1 mm, ±2 mm and ±5 mm in the north, east and height component, respectively. Second, 3 results of full constrained network adjustment under the ITRF94 at the epoch of 2019.0 were obtained: (1) the average accuracy are ±2 mm, ±2 mm and ±6 mm in the north, east and height component, respectively, in the renewal TWD97[2010] network adjustment; (2) the average accuracy are also ±2 mm, ±2 mm and ±6 mm in the north, east and height component, respectively, in the network adjustment which was just only constrained to the KMNM-MUZM baseline; (2) the average accuracy are ±6 mm, ±6 mm and ±16 mm in the north, east and height component, respectively, in the partly renewal TWD97[2010] network adjustment. As the results, it showed that the coordinate system could only be used within 10 years for the requirements of the field surveying at a high level in Taiwan.