GPS應用為未來之趨勢，電離層的影響是其中最大也最難預測的誤差來源，因此本研究主要是用來修正此一誤差。對於GPS單頻接收器使用者無法有效的消除電離層誤差，需要透過某些GPS增益系統，如美國的WAAS系統。而對於GPS雙頻接收器使用者能夠自行估算出電離層誤差，然而有二個因素會影響雙頻使用者估算電離層誤差的精確度，分別是衛星本身的群延遲以及接收器的硬體延遲。本論文使用軟體估算的方法，利用從台灣內政部全球衛星定位系統觀測站的資料來估算衛星及接收器對雙頻訊號所造成的硬體延遲，並利用此修正過後的電離層誤差來開發亞太地區的電離層薄殼模組。同時也利用SOPAC全球衛星定位系統網路上的資料來改善台灣地區電離層模組修正效能。

The ionosphere contributes the largest and most unpredictable error to GPS users’ range measurements. Thus, the goal of this thesis is to correct this error. A single-frequency GPS user needs corrections from some augmented GPS networks, such as the U.S. WAAS (Wide Area Augmentation System). A dual-frequency GPS user takes advantage of the frequency dependence of the ionospheric delay to estimate this term. However, there are two factors which affect the quality of the dual-frequency ionospheric delay estimation, and they are satellite hardware group delay (TGD) and receiver hardware group delay (IFB). This thesis applies a software calibration method to estimate these hardware group delays with the GPS measurements from the GPS network of the SOPAC and MOI. The results of this paper show a promising improvement of the GPS observations. Then use these clean ionospheric delay measurements to develop the standard SBAS thin-shell ionospheric delay model and investigate its performance.

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