Acoustic backscattering in water at the Rayleigh angle

1980 ◽  
Vol 68 (S1) ◽  
pp. S63-S63 ◽  
Author(s):  
Werner G. Neubauer
Keyword(s):  
Acoustic Backscattering ◽  
Rayleigh Angle

Analisis Akustik Target Strength Penyu Hijau (Chelonia Mydas) Melalui Pengukuran Secara Terkontrol Pada Frekuensi 200 kHz

2021 ◽  
Vol 3 (2) ◽  
pp. 94-108
Author(s):  
Teddy Julyansyah ◽  
Deddy Bakhtiar ◽  
Ari Anggoro
Keyword(s):  
Green Turtle ◽  
Population Decline ◽  
Chelonia Mydas ◽  
Total Body Length ◽  
Acoustic Method ◽  
Target Strength ◽  
Acoustic Backscattering ◽  
Total Length ◽  
In Captivity ◽  
Total Body

ABSTRACT Turtles are reptiles that live in the sea and are able to migrate over long distances along the Indian Ocean, Pacific Ocean and Southeast Asia. Currently the number of turtle populations in nature has greatly decreased. This population decline is caused by natural factors and human activities that endanger the population directly or indirectly. At this time the tagging set technique (ID tag code) is a method that is often used to detect the presence of turtles by attaching tags to female turtles who are landing to lay eggs on the beach or while in captivity or the discovery of the mother turtle by fishermen. One other method that can be used to detect the presence of turtles is to use the acoustic method. The purpose of this study was to analyze the characteristics of the acoustic backscattering energy of the green turtle (Chelonia mydes) and to analyze the relationship between target strength and total body length of the green turtle (Chelonia mydas). This research was conducted in the Tapak Paderi waters pond, Bengkulu City, in August-October 2020. The average target strength (TS) value for green turtles was -48.07 dB. Based on the regression equation, the value of determination (R2) obtained is 0.78. Where this value shows that the total length of the green turtle has an effect of 78% on the average target strength (TS) value, while for 22% it is caused by other factors such as body shape, environmental factors and other factors. Based on the ANOVA test, it can be concluded that there is a relationship between the total length and the value of the target strength (TS) on the green turtle or the value of the total length has an influence on the value of the target strength (TS) on the green turtle.  

Acoustic backscattering by Hawaiian lutjanid snappers. I. Target strength and swimbladder characteristics

2003 ◽  
Vol 114 (5) ◽  
pp. 2757 ◽  
Author(s):  
Kelly J. Benoit-Bird ◽  
Whitlow W. L. Au ◽  
Christopher D. Kelley
Keyword(s):  
Target Strength ◽  
Acoustic Backscattering

scholarly journals Acoustic Detection of Oceanic Double-Diffusive Convection: A Feasibility Study

2010 ◽  
Vol 27 (3) ◽  
pp. 580-593 ◽  
Author(s):  
Tetjana Ross ◽  
Andone Lavery
Keyword(s):  
Acoustic Scattering ◽  
Double Diffusive Convection ◽  
Western Antarctic Peninsula ◽  
Acoustic Detection ◽  
Acoustic Backscattering ◽  
Diffusive Regime ◽  
Diffusive Convection ◽  
In Situ Observations ◽  
Double Diffusive

Abstract The feasibility of using high-frequency acoustic scattering techniques to map the extent and evolution of the diffusive regime of double-diffusive convection in the ocean is explored. A scattering model developed to describe acoustic scattering from double-diffusive interfaces in the laboratory, which accounted for much of the measured scattering in the frequency range from 200 to 600 kHz, is used in conjunction with published in situ observations of diffusive-convection interfaces to make predictions of acoustic scattering from oceanic double-diffusive interfaces. Detectable levels of acoustic scattering are predicted for a range of different locations in the world’s oceans. To corroborate these results, thin acoustic layers detected near the western Antarctic Peninsula using a multifrequency acoustic backscattering system are shown to be consistent with scattering from diffusive-convection interfaces.

Acoustic backscattering by deepwater fish measured in situ from a manned submersible

2003 ◽  
Vol 50 (2) ◽  
pp. 221-229 ◽  
Author(s):  
Kelly J. Benoit-Bird ◽  
Whitlow W.L. Au ◽  
Christopher D. Kelley ◽  
Christopher Taylor
Keyword(s):  
Acoustic Backscattering ◽  
Manned Submersible

scholarly journals A comparison of bathymetry mapped with the Simrad ME70 multibeam echosounder operated in bathymetric and fisheries modes

2010 ◽  
Vol 67 (6) ◽  
pp. 1301-1309 ◽  
Author(s):  
George R. Cutter ◽  
Laurent Berger ◽  
David A. Demer
Keyword(s):  
Software Development ◽  
Data Processing ◽  
Bay Of Biscay ◽  
Marine Science ◽  
Dual Use ◽  
Detection Range ◽  
Multibeam Echosounder ◽  
Acoustic Backscattering ◽  
Bathymetric Data ◽  
Phase Data

Abstract Cutter, G. R. Jr, Berger, L., and Demer, D. A. 2010. A comparison of bathymetry mapped with the Simrad ME70 multibeam echosounder operated in bathymetric and fisheries modes. – ICES Journal of Marine Science, 67: 1301–1309. The Simrad ME70 multibeam echosounder was designed for quantitative fisheries research and is currently installed on Ifremer's fishery survey vessel (FSV) “Thalassa” and each of the new, quiet, NOAA FSVs. The ME70 has configurable beams and transmits in the range 70–120 kHz to provide calibrated, acoustic-backscattering data throughout the detection range (fisheries mode, FM). With optional hardware and software, the ME70 can also collect soundings that potentially meet International Hydrographic Organization's S–44 Order 1 standards (bathymetric mode, BM). Furthermore, with custom algorithms and software, bathymetric data can be obtained from the ME70 operating in FM, and volume backscatter can be sampled from the ME70 operating in BM. This flexibility allows data to be concurrently collected on fish and their seabed habitat. A method is described for processing the echo amplitude and phase data from multiple split-beams formed in FM to estimate seabed range, slope, and roughness. The resulting bathymetry is compared with that collected with the ME70 operating in BM in the same area of the Bay of Biscay. A proposal is made for software development to facilitate dual-use data processing.

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