摘要
本論文分兩大部份，第一部份主要在建立一個寬頻掃描的水下聲波成像量測系統，第二部份主要是在探討非線性電子電路負載於水下聲波的應用。
本論文第一部份主要是建立寬頻掃描的水下聲波成像量測系統。為了能夠得到較豐富的傅氏空間資料，所以將使用更多頻率去掃描，以達到寬頻掃描的目的，並且搭配多角度掃描技術，來擷取鋼鐵圓柱體之傅氏空間資料，然後將這些資料經由內插法擺放至直角座標的位置上，最後藉由逆向傅立葉轉換重建影像。藉此了解影像重建原理、傅氏空間擺放方法、二維線性內插法、傅立葉轉換之間的關係與量測校準的重要性。本論文所建立的水下聲波成像量測系統，未來將可應用於海底探測。
本論文第二部份主要是探討非線性電子電路負載於水下聲波的應用。我們利用非線性電子電路負載的特性，以聲波作為訊號源，發射一單頻訊號，經由水下麥克風接收訊號，再將此訊號經過非線性負載電路，再發射一次，量測最終結果，觀察是否有此單頻訊號的倍頻訊號產生。實驗證明在最後量測到的訊號，除了原先的發射訊號之頻率之外，也包含了多個倍頻之頻率分量訊號。本論文所建立的水下聲波之非線性應用之實驗系統，因為可以自動產生倍頻之頻率分量之訊號，未來可應用於水下潛艇之電子戰，即產生假頻率來欺敵。
本論文的研究成果，未來將可應用於水下技術，包括海底探測、水下潛艇之電子戰，並可結合水下通訊發展更進階的水下技術應用。

關鍵詞：水下聲波成像、寬頻掃描、角度掃描、非線性負載、諧波。

Abstract
This thesis includes two subjects. Mainly in the first part is established a measurement system of the underwater acoustic with wideband diversity imaging. The second part is applied non-linear electronic circuit load in submarine.
The first part is to get abundant Fourier space data. In order to achieve the purpose of the wideband diversity, it will be used to scan more frequencies and matching the angular diversity techniques to capture the Fourier space data of metal cylinder and then these scatter data display by bi-linear interpolation to Cartesian coordinates of the position, and finally by two-dimensional inverse Fourier transformation image reconstruction. To understand the principle of image reconstruction, Fourier space display method, two-dimensional linear interpolation method, Fourier transform relationship and the importance of calibration. In this paper, established by measurement of underwater acoustic imaging system, the future can be applied to the seabed to detect.
The second part, takes the signal source by the acoustic wave, launching a base frequency signal, receive signal by hydrophone and passes the nonlinear circuit launching again. Observes whether to have this base frequency signal or other multi-frequencies. Experiments show that in the final measurement of the signal, in addition to the original frequency signals, it also contains a number of frequency components of the signal frequency. In this paper, the experimental system as can be frequency automatically generated the signal can be applied to the future of underwater submarine electronic warfare.
The results presented in this thesis can be applied to the future of underwater technologies, including seabed exploration, underwater submarine electronic warfare, and combined with the underwater communication to develop advanced underwater technology.

Keywords: Image reconstruction, Wideband diversity, Angular diversity, Non-linear load, Harmonic.

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