Underwater acoustic target strength of nets and thin plastic sheets
✍ Scribed by V.G. Welsby; G.C. Goddard
- Publisher
- Elsevier Science
- Year
- 1973
- Tongue
- English
- Weight
- 550 KB
- Volume
- 28
- Category
- Article
- ISSN
- 0022-460X
No coin nor oath required. For personal study only.
✦ Synopsis
The purpose was to find the most suitable material to form a cage, itself having a very small acoustic echo strength, for use in experiments on the acoustic target strength of fish. A series of measurements have been carried out in the Acoustic Tank Laboratory at the University of Birmingham on samples of various materials and a theoretical analysis has been made which gives a useful insight into the way the echo strength depends on the dimensions and mechanical properties of nets and sheets. Sufficient agreement was obtained between theory and practice to show that the results will be valuable for future design work. Plastic sheets were shown to have no advantage over nets. The study has shown that significant effects are caused by surprisingly small amounts of gas adhering to the solid materials. It is this which is likely to set a practical lower limit to the target strengths which can be attained.