- 作者: 陳巽璋; 趙國建; 宋志元; 林士能
- 作者服務機構: 中山大學電機工程學系
- 中文摘要: 光譜儀(Spectrometer)不僅可供一般之光譜分析,同時亦可用以作材料光譜性質的研究。本研究之目的在利用改良式前向一後向線性預測法(Modified forward-backward linear prediction)來提高傅氏轉換光譜儀之估算能力。此種頻譜估測法之基本原理是利用線性預測做外插法,利用現有訊號估測出訊號之自相關函數(Auto-correlation function)來完成頻譜估測之目的,可以準確的用來估測訊號之頻譜分佈或準確地估測訊號之頻率。當然也可以用來估測光訊號之光譜分佈。 除此之外,我們對於光譜訊號之取樣截斷長度、取樣速率、即時處理問題以及雜訊消除等問題也做了詳細的討論。最後,將所得的結果與傳統傅立葉光譜儀做比較,發現本研究所提之方法其品質優於傳統方法。
- 英文摘要: The Fourier Transform Spectrometer (FTS) is essential in the areas of spectral analysis and theinvestigation of the spectrograph of any material. However, interferometric instruments have some seriousdrawbacks, which involve a vast amount of calculation and the fact that their spectrum resolution easily isaffected by the sampling rate, data length and noise. In this paper, a search algorithm for extracting theprincipal eigenvalues is proposed along with the modified forward and backward linear prediction (MFBLP)method to improve upon those weak points. From computer simulations, we have observed that excellentresults could be obtained from only 60 sample points. Furthermore, the presented method also has strongtolerance for low signal to noise ratio. Experiment results will show that the presented method retains theadvantages of interferometric instruments and overcomes their weak points.
- 中文關鍵字: spectrum estimation; interferogram; adaptive line enhancer; modified forward and backward linear prediction
- 英文關鍵字: --