全球定位/氣象(GPS/MET)系統是利用低軌衛星(MicroLab-1)接收全球定位系統(GPS)衛星的雙頻載波相位訊號，經由遮蔽現象來觀測地球的大氣層與電離層。在球對稱的前提下，觀測得到的相位資料可透過偏折角度或全電子含量的計算，藉由Abel積分轉換，反演成電子密度隨高度的分佈圖，在全電子含量的計算法中，為了使反演過程更為即時，將其傳播路徑視為直線，本文中是採用全電子含量計算的方法。為了驗證GPS/MET系統獲得的電子密度隨高度分佈，故和中央大學（中壢；24.6°N，121.0°E）DPS求得的電離層資料相比較，其中是以DPS獲得的電離圖經過自動判讀以及實高析而得到的電子密度隨高度分佈，本文中是使用1996年兩系統觀測得到的資料。 比較結果顯示，由兩系統獲得的F2層的臨界頻率(foF2)和電子密度隨高度分佈的一致性都相當優異，故對於GPS/MET系統得到的電離層資訊的可信度將大大的提升。 The Global Position System/Meteorology (GPS/MET) was to use a low Earth orbiting satellite to receive dual-channel Global Position System (GPS) carrier phase signals and sounding the Earth's atmosphere and ionosphere by radio occultation techniques. Under the assumption of local spherical symmetry, the phase data have been processed through the computation of the bending angel or the total electron content to yield the profiles of ionospheric electron density via the Abel integral inversion. To approach a near-time process, electron density profiles can be derived through computation of the total electron content assuming straight-line propagation. The computation of total electron content was be used in this thesis. In order to assess the accuracy of the GPS/MET ionospheric electron density retrievals, the retrieved electron density profiles from GPS/MET TEC observations have been compared with the ionogram inversion results derived from DPS operated by the National Central University (the Chung-Li digisonde; 24.6°N, 121.0°E). The autoscaling system and true-height inversion processed the ionogram to yield the inversion results. The data were used from the observations of the two systems in 1996 in this thesis. The comparison results show good agreement for both of the derived electron density profiles and the F2-layer critical frequency (foF2). The reliance of the ionospheric information form GPS/MET system raised greatly.
