臺灣水平地表變形模式精度分析與應用

Accuracy Analysis and Applications of Taiwan Horizontal surface deformation model

國家大地基準提供的坐標資訊，若能維持長時間的穩定與精確性，將能有效作為區域內各測繪成果之參考基準以及維護成果精度之用。然而，臺灣目前使用的一九九七坐標系統2010年成果（簡稱TWD97【2010】），由於未有點位坐標的速度值，因此TWD97【2010】仍屬於靜態的大地基準，在複雜的板塊結構環境與其活躍的運動影響下，使得臺灣大地基準之精度維持更為艱辛。自半動態參考框架（semi-kinematic reference frame）概念提出以來，臺灣地區利用歷年GNSS衛星連續觀測站與移動站的資料，陸續推估得臺灣地區半動態參考框架所需的地表變形模式。因此，本研究以臺灣2016、2017年基本控制點的檢測成果以及2018年宜蘭縣、臺東縣加密控制點成果，探討控制點的實測坐標與經水平地表變形模式推算得的坐標之兩者較差，並進行精度驗證，以評估水平地表變形模式應用於臺灣測繪作業的可達精度，作為控制點維護、更新應用的參考資訊。

If the coordinate of control points provided by the National Geodetic Datum can have been maintained its long-term stability and accuracy, it will be able to effectively provide reference coordinates at a high level accuracy for the various applications in the field surveying. However, the 1997 National Geodetic Datum which currently used in Taiwan (TWD97[2010]) is still a static geodetic datum because there is no any velocity information with the coordinate of control points. Therefore, due to the effects of the complex surface plate structures and active plate movements, the accuracy of Taiwan geodetic datum will be more difficult to maintain. Since the semi-kinematic reference frame have been announced, the GNSS continuously operating reference station (CORS) data have been calculated to estimate a horizontal velocity model in Taiwan. In this study, the accuracy of the horizontal velocity field was validated by means of the comparisons between the real coordinates and the predicted coordinates of the basic control points in Taiwan. Secondly, it is proposed to point out the suggestions for the field surveying of basic control points and also to maintain the accuracy and renewal of the control points in all regions of Taiwan.