2005 Fiscal Year Final Research Report Summary
VISUALIZATION AND QUANTIFICATION OF MARINE BIOLOGICAL RESOURCES USING BI-PLANE SCANNING SONAR
| Project/Area Number |
15208017
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
General fisheries
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
IIDA Kohji Hokkaido Univ., Fac.of Fish.Sci., Prof., 大学院・水産科学研究院, 教授 (40142707)
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| Co-Investigator(Kenkyū-buntansha) |
YOSHIMURA Yasuo Hokkaido Univ., Fac.of Fish.Sci., Prof., 大学院・水産科学研究院, 教授 (50322847)
MUKAI Tohru Hokkaido Univ., Fac.of Fish.Sci., Assoc.Prof., 大学院・水産科学研究院, 助教授 (60209971)
MIYASHITA Kazushi Hokkaido Univ., Field Sci.Cent.Northern Biosphere, Assoc.Prof., 北方生物圏フィールド科学センター, 助教授 (70301877)
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| Project Period (FY) |
2003 – 2005
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| Keywords | quantitative sonar / 3-D sonar / visualization / quantification / GIS / acoustic survey / acoustical imaging |
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| Research Abstract |
The scanning sonar can detect fish school much wider area in the water compared to an echo sounder. The purpose of this study is to develop the new generation quantitative scanning sonar to measure the shape, the volume and the density of the fish school for fisheries survey.
1)The quantitative sonar we developed was installed on the fishing boat in Norway and we measured the fish school volume with purse seine fishing for herring and blue whiting. The new sonar was also tested in domestic fishing ground with purse seine fishing for mackerel, squid and yellow tail. Fish schools were detected more than 3,000 meters far from the boat, and the good linear relationship between estimated volume and the catch were found.
2)To estimate density of fish school by echo integration method, the target strength in side aspect is necessary. We measured the 3-dimensional target strength of anchovy in sonar frequencies. The target strength in side aspect agreed well to the TS in dorsal aspect, and it showed the "8" figured directional pattern.
3)To calculate fish number from the fish school volume, the specific occupation volume by a single fish (Tv) is required. We estimated Tv of walleye pollock dividing the volume backscattering strength (Sv) of fish school by the target strength of fish. Results showed that the Tv is proportional to the 2.6th power of the body length.
4)Using the successive multiple sonar images of fish school obtained by the vertical mode, the three dimensional shape of fish school was reconstructed by 3D image processing techniques.
5)Results of the study were presented at fisheries and acoustics symposiums. Some of them were applied for domestic and international patents.
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Research Products
(14 results)
