國際GPS固定站觀測資料品質與定位精度之研究

摘要全球定位系統（GPS）因作業迅速且準確度高，為近幾十年普遍使用之定位技術。但因許多因素，導致其定位精確度下降、影響定位精度的品質。其影響定位精度的多種因素，在國際上已有相當多的研究為了探討GPS觀測資料品質與基線解算精度間之關聯性，本文的研究目的是將針對全球GPS衛星追蹤站近三年內曾更換過儀器的測站來分析，更換前後的定位精度與資料品質的差異。本研究採用了六項觀測資料品質指標，分別為觀測資料量、週波脫落數、L1的多路徑效應、L2的多路徑效應、接收儀時錶偏移量與接收儀時錶穩定度。因此，本研究對於定位精度的影響的六項指標中最重要為時錶誤差分別為接收儀內部時鐘頻率穩定度（stability）及接收儀內部時鐘平均偏移量（offset），第二為週波脫落(o/slps)，最後為觀測資料量(obs)及多路徑效應(mp1＆mp2)對於定位精度的影響，作為資料指標重要的數據品質。例如說時錶誤差過大的時候，定位精度就明顯的比較差，所以就可以對幾項的指標資料作監控，來分析GPS觀測資料品質指標跟定位精度指標的相關性，期望能提供未來的使用者在選用GPS量測設備之參考，並期望能透過GPS觀測資料的品質監控，進而提昇GPS量測之精度。

關鍵字

全球定位系統；資料品質；定位精度

並列摘要

Abstract The Global Positioning System (GPS) is a common surveying technology of the world in the decade years, because of its convenience and high accuracy. However, the positioning precision will be influenced by many factors..Recently there have been more than three thousand permanent GPS stations set up for evaluating the relationship between data quality and baseline resolution precision. The criteria chosen for verifying GPS data quality are the quantity of the stability of receiver’s clock , the multipath effect of L1 , the multipath effect of L2 observation data , the cycle slips and the receiver’s clock error .Among those crit。eria, the fp has the major effect on the data quality. The mp1 and mp2 has less effect and the obs and o/slips has minor effect on data quality. The tp has the least effect on dataquality.The data quality of the chosen permanent GPS stations will be estimated using the above mentioned criteria. The weight of each criterion will also be considered in the study. The reliability of each GPS station will be analyzed based on this results and announced for reference.