Ocean ambient noise is one of the important parameters which affect sonar system performance. If the ocean ambient noise is estimated accurately, the prediction accuracy of sonar system performance can be promoted significantly. Ocean ambient noise includes various and diverse sources, so the characteristics of the ocean ambient noise should be analyzed by long-term observations and statistical methods. Therefore, ocean ambient noise database was developed to facilitate management, preservation, and application of these datasets which increase with time. There were two datasets of acoustic and three datasets of wind speed in this database at this point. To develop this database systematically, this study applied Entity-Relationship Model to describe the relationship between different data and Relational Model to design the required categories. The database was constructed based on Microsoft Office Access, and user-friendly graphical interfaces based on MATLAB were provided for users: wind speed regression, time series, spectrogram, and spectrum tendency for users to query the database. As the results of analysis, the intermittent, unknown, and high-level sources at southwestern sea of Taiwan in spring and summer made the noise level of low frequency about 8 to 10 dB higher in the night-time than that in the day-time. According to wind speed regression analysis, if there were sufficient data, the method would be practicable to pick a wind speed data nearby the location of acoustic data for noise estimation. As the results of the typhoon effects analysis, the noise level of 1 to 8 kHz was increased significantly by typhoons. Besides, the noise level didn¡¦t decrease immediately and significantly after the pass of typhoon because of southwestern air current caused typhoon. After the database was developed, new acoustic data will keep being measured and collected, and the network capability will be integrated into the database to make the database more accessible to users.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0826109-224737 |
| Date | 26 August 2009 |
| Creators | Wu, Chih-Hao |
| Contributors | Shiuh-Kuang Yang, Ruey-Chang Wei, Shih-Chieh Jack Hsu |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0826109-224737 |
| Rights | unrestricted, Copyright information available at source archive |
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