本論文利用傅利葉分析(Fourier Analysis)討論電離層週期性振盪之垂直群速與相速，以此方法分析電離層探測儀（ionosonde）與特高頻(Very High Frequency, VHF)觀測資料而獲知電離層垂直波動之傳播。 首先利用模擬對群速與相速分析方法進行驗證。在模擬中以加成與倍乘形式加入雜訊干擾，以討論雜訊對分析結果造成之影響與分析方法之穩定性。 資料分析方面，針對電離層暫態層和常態層伴隨之垂直波動傳播加以研究及探討。暫態層波動以赤道異常區（equatorial anomaly region）日食F1層和赤道地區電離層增層(additional layer)為例，而常態層波動則以中緯度F2層為代表。研究日食對電離層之影響，其結果發現短時間內太陽光強度迅速變化可引發F1域(F1 region)波動，而其波動源接近F1層峰。研究電離層增層形成時伴隨之波動，結果顯示增層層峰附近是為波動源所在。以電離層探測儀與特高頻雷達同時觀測F2層波動，發現其波源所在高度於F2層峰上方。綜合以上結果，電離層層峰附近是為波動能量源之所在。 In this dissertation, a procedure deriving the vertical group and phase velocities of periodic waves in the ionosphere is proposed. The method is based on Fourier analysis and considered the difference of angular frequency and wave number as a function of number of data points used in a spectral analysis. Simulations and observations from ionosondes and a VHF radar are investigated to understand the vertical propagation and source of the waves. The simulation is employed to demonstrate the usefulness of the procedure while some noises are added and multiplied to the wave packet for examing the suitability and stability of the procedure. The developed procedure is further applied to analyze waves appearing in transient layers during a solar eclipse and appearance of an additional sub-layer as well as a permanent layer of the F-region. A study of the waves caused by repid change of sunlight during the solar eclipse shows that the energy source lies at the altitude near the F1 peak. An examination of the waves during appearance of the additional layer in the equatorial regions indicates the wave source is around the peak of the layer. An analysis of the data observed from ionosonde and the VHF radar, the F2 peak is an energy source of the associated waves. Results of this dissertation demostrate the waves sources are mainly around the peaks of layers in the ionosphere.
