過去的研究，大多討論下層電離層電子濃度的變化，鮮有對於上層電離層和電漿層全電子含量之全球長期觀測討論。本論文利用福爾摩沙衛三號上精密衛星軌道定位天線所接收GPS衛星訊號，計算訊號行徑之延遲量。藉此估算自衛星高度800公里到GPS衛星高度(20200公里)之全電子含量。另外，反演掩星觀測實驗記錄以獲得電離層電子濃度垂直分佈，並計算其90-800公里之電離層全電子含量。科學家已利用全球定位系統之世界網站，建構全球電離層全電子含量圖GIM，例行公布地表至20200公里之全電子含量。因此將GIM全電子含量減去GOX的亦可推估800-20200公里全電子含量。分析比較2007-2008年兩種800-20200公里之電漿層電子含量資料的日變化與季變化。結果顯示，在緯度變化方面，電漿層電子含量自磁赤道向兩極遞減，而且不具有南、北半球季節不對稱之現象。在經度變化上，沿磁赤道觀測到數個高含量區域，且在大西洋與南美洲海陸交界處具有顯著的季節差異。

Previous studies examine changes of the electron density in the bottomside ionosphere, and however the total electron content (TEC) of the topside ionosphere and/or the plasmasphere has not been investigated in detail. This thesis derives the TEC from 800km to 20200km, termed the plasmaspheric electron content (PEC), by excess time delay of GPS signals recorded by the POD antenna onboard FORMOSAT-3/COSMIC (F3/C). Meanwhile, the electron density profile and its associated TEC (IEC) from 90km to 800km can be derived by using radio occultation technique in GPS Occultation Experiment of F3/C. On the other hand, the TEC from the ground to the 20200km of the GPS satellite altitude (GEC) of Global Ionospheric Map (GIM) are routinely reported every two hours. Therefore, the difference between GEC and IEC (i.e. DEC) also represents the TEC between 800km and 20200km. Both diurnal and seasonal variations of the PEC and GEC in 2007 and 2008 are investigated Results show that PEC/DEC decrease polarward from magnetic equator and yield symmetry futures the southern and northern hemisphere in each season. In longitude, there are some PEC/DEC peaks alone the magnetic equator which reveal an obvious the seasonal difference between the Atlantic and South America area.

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