| Summary: | 碩士 === 國立中央大學 === 電機工程研究所 === 94 === 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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