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| 研究生： |
林鴻志 Hong-Zhi Lin |
|---|---|
| 論文名稱： |
雷達訊號之時頻分析 Time-Frequency analysis of radar signal |
| 指導教授： |
劉兆漢
Chao-Han Liu |
| 口試委員: | |
| 學位類別： |
碩士 Master |
| 系所名稱： |
資訊電機學院 - 電機工程學系 Department of Electrical Engineering |
| 畢業學年度： | 94 |
| 語文別： | 中文 |
| 論文頁數： | 92 |
| 中文關鍵詞： | 基波轉換 、希爾伯-黃轉換 、自動化濾波 、都卜勒速度 |
| 外文關鍵詞： | Hilbert-Huang Transform, Wavelet Transform, Doppler frequency shift, Auto-filtering process |
| 相關次數： | 點閱：13 下載：0 |
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本文利用中壢特高頻雷達在觀測大氣訊號時，常有雜訊污染訊號，使訊號無法有效利用。在本研究中，主要針對飛機及降雨對雷達訊號的干擾來進行濾波，而使用的方法為新技術希爾伯-黃轉換（Hilbert-Huang Transform，HHT），在濾除飛機訊號時，也藉助基波轉換（Wavelet Transform，WT）在數學上的貢獻，與HHT相輔相成，有效率的進行濾波，最後而發展了一套「自動化濾波」。而濾波結果彼此比較都卜勒速度、頻寬、頻譜等，判斷是否正確，最後再看看其結果是否在雷達訊號裡接近大氣的波動，使其有效再利用與分析。
When we use Chung Li VHF radar to observe atmospheric signal, there are some noise make the signal feckless. In this study, we use wavelet transform and a new method called Hilbert-Huang Transform to filter the plane and precipitation signal, that is, the noise. By this way, we create a process called "auto-filtering process" to filter the noise from normal atmospheric signal. 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. After comparing these outcomes with normal atmospheric signal, we can determine if the method is useable.
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