應用非監督式分類技術於臺灣地表速度場之區塊模型建立

Block Modeling of Surface Velocity Field In Taiwan Based On Unsupervised Classification Technique

盧姵均(Pei-Chun Lu)

指導教授 ： 韓仁毓

國立臺灣大學/工學院/土木工程學研究所/碩士(2021年)

https://doi.org/10.6342/NTU202101788

摘要

臺灣位於歐亞大陸板塊以及菲律賓海板塊交界處，頻繁發生地震造成位移以及變形量快速累積，且依所在區域不同而造成方向以及數值的差異。測量成果仰賴基準，目前我國採用靜態基準，為將控制點的精度維持在規範內，政府採取重測作業維護基準，然此方法耗費時間及人力成本。本研究欲簡化臺灣的複雜的地表運動情形，故採用分佈於臺灣地區共374個GNSS連續觀測站將其組成不規則三角網方法搭配剛體運動理論獲得尤拉參數，再將特徵以K-means及ISODATA兩種演算法進行非監督式分類，以獲得基於資料特性之成果。從分群成果中可獲得區塊內殘餘的地表運動數值，且評估尤拉參數對於共同運動訊號吸收程度，最後納入我國施行法規探討區塊基準的使用年限。在此方法流程下，分群成果將臺灣運動情形分為北、中、南、東四個部分，區塊內尤拉參數可吸收控制點內約40%至90%的地表共同運動行為。根據相對速度場計算獲得，於衛星定位測量一等精度下，北部區塊基準使用年限可至23年，中部區塊為10年，南部區塊為9年，東部區塊為6年。除相對運動顯著之東部區塊外，各區塊基準使用年限與我國內政部約每十年更新TWD97基準頻率接近，故建立區塊獲得相對速度場可做為一建立地表運動行為模型之選擇方案。

關鍵字

全球導航衛星系統 ； 速度場模型 ； 尤拉運動分析 ； 非監督式分類

並列摘要

Taiwan is located at the plate boundary between the Eurasian plate and Philippine Sea plate, the displacement varies from directions and values in different area. The quality of measurement result is based on the datum. Taiwan government adopts static datum as current standard; however, it needs to re-survey regularly in order to obtain high accuracy measurement results. Re-surveying consumes both time and labor costs a lot. This study aims to simplify the complex surface motion in Taiwan, and uses 374 GNSS observation stations to form triangulated irregular network. With this method, this study obtains features with the GNSS reference stations location and Euler’s theorem, and they are classified by K-means and ISODATA. This study evaluates the relative surface motion and the absorption to the common surface motion behavior by Euler parameters according to the cluster result. Finally, the result should follow current regulations, and with this result can evaluate frequency to renew the geodetic datum. Consequently, Taiwan is divided into four blocks: North, Central, South, and East. The Euler parameters in the block can absorb about 40%-90% common surface motion behavior. According to the analysis results of the relative velocity field, the north block datum can be used for 23 years, the middle one can be used for 10 years, the west one can be used for 9 years, and the east one can be used for 6 years under the first-class accuracy of the satellite positioning measurement. Except east block, the datum renew frequency of each block is close to the frequency of TWD97. In summary, the relative velocity field under cluster blocks can be used as an option to model the surface motion behavior

並列關鍵字

Global Navigation Satellite System(GNSS) ； Velocity Field Model ； Euler’s Theorem ； Unsupervised Classification

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