2006年4月我國和美國雙邊合作發射福爾摩沙衛星三號,主要是利用電波掩星觀測技術觀察大氣結構。六顆低軌道衛星組合之星系皆載有全球定位系統氣象量測儀,因此可以量測全球電離層電子濃度之垂直分布。本論文收集2006年以來完整一整年的資料,藉此予研究電離層日季變化、太陽活動極小期及經緯變化之全球電子濃度三維結構及其相關動力機制。 To observe ionospheric structure by using the radio occultation (RO) technique, the joint Taiwan-US satellites of Formosa Satellite 3 and Constellation Observing System for Meteorology, Ionosphere, and Climate (FORMOSAT-3/COSMIC or F3/C in short) were launched 14 April 2006. This thesis analyzes data from July 2006 till June 2007. To investigate the 3-D ionosphere electron density structure and dynamics of the diurnal, seasonal, and geographical variations.