GPS衛星播送的訊號在經過電離層時，會使得其中的電碼訊號造成延遲，對於GPS衛星定位有極大的影響，本論文特別使用台灣自主電離層數值模式(TWIM)來作電離層延遲修正。在測站與參考站接收到的單頻GPS電碼訊號資料，將電離層延遲以及其他偏差修正後，經由差分定位法(DGPS)運算可達到次公尺等級的定位精準度。本論文的宗旨即是將TWIM模式與DGPS定位法作整合，推廣至Android作業系統平台的應用程式(APP)，來呈現出本論文研究的概念性應用。 本篇論文研究的定位成果，將藉由定位方法的比較來呈現，並將延伸分析DGPS定位法裡測站與參考站的基線長度對定位殘差的影響。 When GPS signals pass through the ionosphere, it would produce signal delay in code measurements. This ionospheric delay would affect the GPS positioning results. In this study, a single-frequency Novatel receiver has been setup as a test station, and the ionospheric delay has been simulated and corrected using the TaiWan Ionospheric Model(TWIM). After the ionospheric delays are simulated and corrected, a differential GPS(DGPS) technique could be applied for positioning and approach a sub-meter positioning accuracy. We also developed an Android APP tool and promote real-time dGPS positioning after correcting ionospheric delay based on the TWIM. In the thesis, the results would be demonstrated and evaluated by comparisons of different positioning methods. Besides, it would show positioning accuracy related to baseline length between the test and reference stations.
