本次觀測事件是利奇馬颱風侵台期間，位於中壢的特高頻雷達對此颱風做連續時間的觀測，其觀測時間從2001年9月24日14:00 LT至28日00:00 LT。在本研究中，我們將求出資料的回波功率、都卜勒頻移量、都卜勒頻寬、訊號雜訊與頻譜，並利用高斯分布函數逼近中性大氣頻譜，以求出中性大氣的徑向速度。本論文中，嘗試利用HHT時頻分析法以及群速與相速分析法研究分析此颱風期間中性大氣垂直徑向速度的波動現象。 During the passage of Typhoon Lekima, a continuous observation was made with a VHF radar located in Chung-Li, Taiwan. The observation period was from September 24 14:00 LT to 29 00:00 LT, 2001. In the thesis, we used the observed data to calculate the echo power, the Doppler frequency shift, spectral width and signal-to-noise ratio by the moment method. We also calculated the spectra of the data and obtained the radial velocity by fitting the Gaussian function to the turbulence spectral component. To analysis the waves of radial velocity during the typhoon period, we use the Hilbert Huang Transform and the vertical phase and group velocities method.
