碩士 / 國立臺灣大學 / 工程科學及海洋工程學研究所 / 94 / The fast sound speed at sea surface in the waters surrounding Taiwan causes strong refraction of sound waves. If water depth is less than five thousand meters, the sound waves will be reflected at the seafloor. Therefore, geo-acoustic properties are important to the acoustic study in the water surrounding Taiwan.
This thesis composes of two major works. Part I is the inversion of pressure wave attenuation coefficient from chirp sonar data. Part II is to establish the geo-acoustic model for different sediment types, thus to provide for the Advanced Sonar Range Prediction System (ASORPS).
In the past, has been used spectral ratio technique obtain geo-acoustic parameters from 3.5 kHz sonar data. Now the sediment exploring technique has already advanced using chirp sonar system on Ocean Researcher I and Ta Kuan’s TOPAS system. The data of chirp sonar collected in Ocean Researcher I has not been analyzed to retrieve the geo-acoustic parameters yet. Therefore, one part of this study presents the estimation of attenuation coefficient of the seafloor sediment obtained by analyzing the Ocean Researcher I chirp sonar data. The results are compared with the core data, and the error is within 15%.
Another purpose of this research for the geo-acoustic model of Taiwan''s surrounding sea was to establish information needed. Also, the concept and framework of a geo-acoustic database is proposed.
| Identifer | oai:union.ndltd.org:TW/094NTU05345004 |
| Date | January 2006 |
| Creators | Cheng-Che Lee, 李政哲 |
| Contributors | Chi-Fang Chen, 陳琪芳 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 130 |
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