臺灣區域性對流層延遲修正模式之介紹

The Introduction of Regional Tropospheric Correction Model over Taiwan

吳曉雯(Hsiao-Wen Wu) ； 楊名(Ming Yang) ； 李孟穎(Meng-Ying Li) ； 江凱偉(Kai-Wei Chiang)

《地籍測量：中華民國地籍測量學會會刊》 30卷2期 (2011/06) Pp. 1-16

https://doi.org/10.29609/YYWYLL.201106.0001

摘要

對流層延遲誤差是衛星定位主要的誤差來源之一，對流層誤差根據其特性可以進一步分為乾分量及濕分量，透過全球經驗模式配合精確的地面氣象量測值，可獲得公厘精度等級之天頂方向之對流層乾延遲估值。濕延遲量則與水汽含量的多寡有關，水汽含量較多時，濕延遲量也相對較高。然而，水汽在空間及時間上具有快速變化之特性，因此限制了濕延遲量估計之精度。本文說明臺灣區域性對流層延遲模式使用之相關資料，資料內容主要包含2009年臺灣國土測繪中心之全球定位系統衛星追蹤站(e-GPS)觀測資料以及中央氣象局之地面氣象觀測網數據，並且說明此區域性模式相關公式以及使用方法。結合氣象觀測網數據、GPS觀測網及克利金方法所推估之e-GPS氣象量做為乾延遲計算之輸入值，成果分析顯示14個檢核站之平均RMS約為±0.23cm。另一分析則是將區域模式與使用標準大氣參數之全球經驗模式相比，結果顯示以此技術所發展出的區域性模式更能表現出臺灣地區對流層延遲量的季節變化趨勢。此外，將此區域性模式與GPS實測資料兩者相比，藉由分析14個均勻分布的獨立檢核點相關數據，其精度可達到±4.77cm。藉由檢核成果說明了結合氣象觀測網與GPS觀測資料可以輔助建立一個精度良好的區域性對流層修正模式。

關鍵字

地面氣象觀測 ； 絕對天頂對流層延遲 ； 區域性對流層延遲模式

並列摘要

Tropospheric delay is one of the major error sources while positioning. According to the characteristics of tropospheric delay, it can be divided into two parts, dry and wet component. By adopting global tropospheric delay model and surface meteorological data, the accuracy of dry component in the zenith direction can reach to mm level. While the wet delay is related to the amount of water vapor, the accuracy of estimating wet delay is limited due to the quickly spatial and temporal changes of water vapor. In this study, we also introduce the regional tropospheric delay model developed via data from GPS observation and meteorological data in 2009. The GPS observation sites (e-GPS) were set up by National Land Surveying and Mapping Center (NLSC) and the meteorological surface station were set up by the Central Weather Bureau (CWB). Formulas and the process of using this regional tropospheric model are also introduced in this study. By combining the meteorological data, GPS data and Kriging method, the average of RMS among 14 check stations can reach to ±0.23cm. The regional model shows the seasonal variation and consists with the GPS-estimated ZTD by comparing to the global models that using standard atmosphere. The overall accuracy of the model is ±4.77 cm, as is evaluated at 14 evenly distributed check points. According to the results, it is a feasible technique to develop an accurate regional tropospheric delay model by using the meteorological data and GPS data.

並列關鍵字

Surface meteorological measurement ； absolute zenith tropospheric delay ； regional tropospheric delay model