台灣GPS連續觀測站坐標時間序列分析方法研究

Analysis of Coordinate Time Series of Taiwan Continuous GPS Stations

近年來，利用GPS連續觀測資料來研究板塊運動及地殼變形之技術已趨近成熟，在進行長時間的GPS計算過程中，需要一合理且可靠的坐標參考框架。台灣位於板塊邊界、地震活動頻繁的地區，其最大的困擾是International GNSS Service（IGS）參考站離觀測網太遠，造成解算時較大的誤差，解決方法即是建立屬於台灣地區的坐標參考框架。本文自1995至2005年底之IGS參考站中，選取資料穩定、連續性佳、資料時間長、速率穩定、網形幾何分佈良好之連續站作為國際約制站，進而解算國內約制站（CK01、KDNM、KMNM、S01R、TNML）的坐標及速度值。利用ITRF2005框架，並濾除因地震和更換儀器等因素造成改變，從而最新公告的新坐標及速度值；再利用誤差傳播定律求得合理的坐標約制量；此外經由空間濾波技術處理時間序列，可改善時間序列中所造成的共同誤差之影響量及有效降低離散程度。 Continuous GPS observation technology has largely improved the capability of monitoring on plate motion and crustal deformation. During the data processing, rational and reliable reference frame is needed. The GPS network in Taiwan is located away from the IGS reference frame network stations, and therefore large uncertainty may be occurred during the processing procedures. To resolve the problem, choosing the continuous GPS stations of Taiwan to set up a reference frame of Taiwan is necessary. In the study, we selected the IGS continuous stations of stability and duration in the interval of 1995–2005 to establish an appropriate distributed network. Furthermore, we also calculated the coordinate and velocity of permanent constrained Taiwan GPS stations(CK01、KDNM、KMNM、S01R、TNML). This research refers to the ITRF2005 reference frame. The influence of earthquake and changing instrument has been considered. We obtained the reasonable coordinate constraint value by using the error propagation. Furthermore we reduced the common errors by using the spatial filtering technique, improving the scattering in the time series.

Continuous GPS observation technology has largely improved the capability of monitoring on plate motion and crustal deformation. During the data processing, rational and reliable reference frame is needed. The GPS network in Taiwan is located away from the IGS reference frame network stations, and therefore large uncertainty may be occurred during the processing procedures. To resolve the problem, choosing the continuous GPS stations of Taiwan to set up a reference frame of Taiwan is necessary. In the study, we selected the IGS continuous stations of stability and duration in the interval of 1995–2005 to establish an appropriate distributed network. Furthermore, we also calculated the coordinate and velocity of permanent constrained Taiwan GPS stations（CK01、KDNM、KMNM、S01R、TNML）. This research refers to the ITRF2005 reference frame. The influence of earthquake and changing instrument has been considered. We obtained the reasonable coordinate constraint value by using the error propagation. Furthermore we reduced the common errors by using the spatial filtering technique, improving the scattering in the time series.