有關赤道電離層F擴散(spread)現象的原因與物理機制,一直是研究電離層的學者所感興趣的,本篇論文是利用中華衛星一號(ROCSAT-1)IPEI酬載,將觀測在高度600Km,南北緯35度之間的電離層F層中離子密度與速度變化的資料,作頻譜分析並將頻譜分析的結果分為三個波長範圍來討論,找出在不同波長的範圍內,其波譜指數(spectral index)變化情形,並與其他作者所得之結果,做一比較;其中較特別的是,由於中華衛星一號(ROCSAT-1)的高空間解析度,我們將首次可得到高頻部分的資料,並對此資料作一初步的分析與整理。 The most spectacular phenomenon that occurs in the nighttime ionosphere is the F-region equatorial spread-F(ESF) event. The so-called plasma bubble in ESF can occur shortly after sunset and lasts till sunrise. There have been many theoretical and experimental investigation of ESF event in the past twenty years. However, ROCSAT-1 IPEI payload observation of the ESF event has one new result, that is the first observation of ESF in the transition scale (10-100m) by a satellite borne instrument. This thesis will study a couple of ESF events in three scale ranges, medium scale (10-1000Km), intermediate (100m-10Km) and transitional scale (10-100m).