Inversion of Sound Speed and Thickness of High-Speed Sediment Using Interference Structure in Shadow Zone
The geoacoustic parameter acquisition in the deep sea is of great significance to the research of ocean acoustics. This paper found that the interference structure of the shadow zone induced by the reflection of the high-speed sediment layer could be simply described by the grazing angle of the surf...
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MDPI AG
2022-05-01
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| Series: | Applied Sciences |
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| Online Access: | https://www.mdpi.com/2076-3417/12/10/5077 |
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| author | Zhanglong Li Changqing Hu Mei Zhao |
| author_facet | Zhanglong Li Changqing Hu Mei Zhao |
| author_sort | Zhanglong Li |
| collection | DOAJ |
| description | The geoacoustic parameter acquisition in the deep sea is of great significance to the research of ocean acoustics. This paper found that the interference structure of the shadow zone induced by the reflection of the high-speed sediment layer could be simply described by the grazing angle of the surface-bottom reflection from the theory of ray acoustics, when the source and receiver depth makes the grazing angle of the surface-bottom reflection consistent with that of the bottom-surface reflection. On this basis, a geoacoustic parameter inversion method by spatial position matching of interference fringes in the shadow zone was proposed, and an interference fringe extraction method was designed based on the maximum between-class variance algorithm in this paper. After extracting the results by the stripe coordinates in the simulation environment, the density was obtained by assuming the base sound speed as an empirical value and combining with Hamilton’s empirical formula, and the sediment sound speed and thickness were inverted by the grid search method. Those inversion results were compared with the multi-dimensional inversion results of the genetic algorithm. The simulation results showed that the fringe extraction method proposed in this paper could effectively extract the interference fringes formed by the reflection of the high-speed sediment in the shadow zone, and compared with the multi-dimensional optimization process, the relatively accurate inversion results of the sound speed and thickness of high-speed sediment could be obtained more effectively and quickly by taking the spatial position of the interference fringe as the cost function of the matching parameter combined with the grid search method in this paper. |
| first_indexed | 2024-03-10T03:23:36Z |
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| id | doaj.art-a379a07fd7774ee6a7d648a75cf202e2 |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-10T03:23:36Z |
| publishDate | 2022-05-01 |
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| spelling | doaj.art-a379a07fd7774ee6a7d648a75cf202e22023-11-23T09:57:25ZengMDPI AGApplied Sciences2076-34172022-05-011210507710.3390/app12105077Inversion of Sound Speed and Thickness of High-Speed Sediment Using Interference Structure in Shadow ZoneZhanglong Li0Changqing Hu1Mei Zhao2Shanghai Acoustics Laboratory, Institute of Acoustics, Chinese Academy of Sciences, Shanghai 201815, ChinaShanghai Acoustics Laboratory, Institute of Acoustics, Chinese Academy of Sciences, Shanghai 201815, ChinaShanghai Acoustics Laboratory, Institute of Acoustics, Chinese Academy of Sciences, Shanghai 201815, ChinaThe geoacoustic parameter acquisition in the deep sea is of great significance to the research of ocean acoustics. This paper found that the interference structure of the shadow zone induced by the reflection of the high-speed sediment layer could be simply described by the grazing angle of the surface-bottom reflection from the theory of ray acoustics, when the source and receiver depth makes the grazing angle of the surface-bottom reflection consistent with that of the bottom-surface reflection. On this basis, a geoacoustic parameter inversion method by spatial position matching of interference fringes in the shadow zone was proposed, and an interference fringe extraction method was designed based on the maximum between-class variance algorithm in this paper. After extracting the results by the stripe coordinates in the simulation environment, the density was obtained by assuming the base sound speed as an empirical value and combining with Hamilton’s empirical formula, and the sediment sound speed and thickness were inverted by the grid search method. Those inversion results were compared with the multi-dimensional inversion results of the genetic algorithm. The simulation results showed that the fringe extraction method proposed in this paper could effectively extract the interference fringes formed by the reflection of the high-speed sediment in the shadow zone, and compared with the multi-dimensional optimization process, the relatively accurate inversion results of the sound speed and thickness of high-speed sediment could be obtained more effectively and quickly by taking the spatial position of the interference fringe as the cost function of the matching parameter combined with the grid search method in this paper.https://www.mdpi.com/2076-3417/12/10/5077interference structure in shadow zoneinterference fringe extractiongeoacoustic parameter inversion |
| spellingShingle | Zhanglong Li Changqing Hu Mei Zhao Inversion of Sound Speed and Thickness of High-Speed Sediment Using Interference Structure in Shadow Zone Applied Sciences interference structure in shadow zone interference fringe extraction geoacoustic parameter inversion |
| title | Inversion of Sound Speed and Thickness of High-Speed Sediment Using Interference Structure in Shadow Zone |
| title_full | Inversion of Sound Speed and Thickness of High-Speed Sediment Using Interference Structure in Shadow Zone |
| title_fullStr | Inversion of Sound Speed and Thickness of High-Speed Sediment Using Interference Structure in Shadow Zone |
| title_full_unstemmed | Inversion of Sound Speed and Thickness of High-Speed Sediment Using Interference Structure in Shadow Zone |
| title_short | Inversion of Sound Speed and Thickness of High-Speed Sediment Using Interference Structure in Shadow Zone |
| title_sort | inversion of sound speed and thickness of high speed sediment using interference structure in shadow zone |
| topic | interference structure in shadow zone interference fringe extraction geoacoustic parameter inversion |
| url | https://www.mdpi.com/2076-3417/12/10/5077 |
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