以連續運行基站（CORS）建立城市級對流層延遲模型－以臺中市為例

Modeling City-level Tropospheric Delay Using Continuously Operating Reference Station (CORS)－A Case Study of Taichung City

本研究利用臺中市新設10個分布於臺中市地區之衛星基準站，使用精密單點定位（Precise Point Positioning, PPP）技術推算出天頂對流層延遲量，並結合大臺中地區地面氣象站所觀測之氣象資料，以建立一個能呈現臺中市地區對流層延遲實際時空變化之天頂對流層延遲修正模型。研究成果顯示，臺中市地區對流層乾、濕延遲量會呈現不同的分布趨勢，因此須分別對乾、濕延遲量建立修正模型。使用本研究建立之城市級對流層延遲修正模型後，坐標之定位距離誤差從原本約100～120公分，下降到60公分以內，減少了40～60公分之誤差量，可有效提升精密單點定位之成果。

This study aims at the 10 newly set satellite reference stations in Taichung city, using the Precise Point Positioning technique to calculate the zenith tropospheric delay amount, and combine with the weather information from the surface weather observation station in Taichung, building a revised model of zenith tropospheric delay that shows the actual spatial variation of tropospheric delay of Taichung city. The result shows that, the dry and wet delays of troposphere in Taichung have different distributions. Therefore, we need to build up a revised model for dry and wet delay separately. And the distance deviation of coordinates is lowered down within 60cms from 100~120cms, reducing the deviation of 40~60cm. It has great effects on the results of precise point positioning.