Measurement of the Dimensions of Fish to Facilitate Calculations of Echo-Strength in Acoustic Fish Detection

Haslett, R.W.G.

doi:10.1093/icesjms/27.3.261

Cited by 15 publications

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“…Andreeva and Chindonova (1964) simplified equation (2) io(H + 30)^/ 2 f. = 1.5 (Vbi) i/3 where f^is in kHz, H is the depth in meters, and W^\ is the volume of the swimbladder in mm^. From Haslett's consideration of fish dimensions (Haslett, 1962), fish volume is related to fish length (L) by the expression Vfi3h = 0.01 l3. 4Following Marshall's assumption (1951) that the volume of the swimbladder in a marine fish is about 5 percent of the volume of the fish, the swimbladder volume can be expressed as Vbi = 5 X 10 ""^l 3, (5) By combining equations (3) and 5an expression is given for fish length as 'r where L is in cm.…”

Section: Discussionmentioning

confidence: 99%

Biological sound scattering studies

1970

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De1-ailed knowledge of a variety of oceanographic parameters is required to fully understand the effect of the ocean environment on sound transmission. One parameter which significantly influences sound propagation is the backscattering or volume reverberation caused by marine organisms. The Naval Oceanographic Office is conducting an interdisciplinary research program to investigate the scattering of sound by marine organisms; in particular, this effort includes studies to determine the acoustic, biological and oceanographic properties of sound scattering layers, as well as the relationships between these properties. This report is the first of several concerning the results of biological studies being conducted to investigate volume reverberation in the ocean.

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Section: Discussionmentioning

confidence: 99%

Biological sound scattering studies

1970

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“…Swimbladders have been considered to be the dominant scattering mechanism based on estimates that swimbladders cause as much as 90-95% of the target strength of fish under certain conditions due to the large acoustic contrast between the air-filled swimbladder and the surrounding tissue and water (Foote, 1980). Their influences on the acoustic signatures have been studied intensively by Jones and Pearce (1958), Andreyeva (1964), Weston (1967, Haslett (1962c), Hawkins (1977), Love (1978) and Foote (1980Foote ( , 1985. While the size and shape of swimbladders may dominate the scattering properties of fish, other parts of the anatomy create acoustic impedance contrasts which contribute, particularly for fish without swimbladders, to the overall scattering, e.g., skull, vertebral column, muscle tissue and gonads.…”

Section: Morphologymentioning

confidence: 99%

“…At swimbladder resonance frequencies, backscattering cross section varies with fish size and frequency. In the geometric scattering region at higher frequencies, it depends on multiple scattering features in the fish which wil cause interference in a manner specific to its anatomy, and that interference pattern is dependent upon frequency (Haslett, 1962c). In other words, the physical separation of scattering features in the fish relative to acoustic wavelength determines the interference pattern.…”

Section: Behavior and Physiological Changesmentioning

confidence: 99%

Acoustic scattering by axisymmetric finite-length bodies with application to fish : measurement and modeling

Reeder¹

2002

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This thesis investigates the complexities of acoustic scattering by finite bodies in general and by fish in particular through the development of an advanced acoustic scattering model and detailed laboratory acoustic measurements. A general acoustic scattering model is developed that is accurate and numerically effcient for a wide range of frequencies, angles of orientation, irregular axisymmetric shapes and boundary conditions. The model presented is an extension of a two-dimensional conformal mapping approach to scattering by irregular, finite-length bodies of revolution. An extensive series of broadband acoustic backscattering measurements has been conducted involving alewife fish (Alosa pseudoharengus), which are morphologically similar to the Atlantic herring (Clupea harengus). A greater-than-octave bandwidth (40-95 kHz), shaped, linearly swept, frequency modulated signal was used to insonify live, adult alewife that were tethered while being rotated in 1-degree increments over all angles of orientation in two planes of rotation (lateral and dorsal/ventral). Spectral analysis correlates frequency dependencies to morphology and orientation. Pulse compression processing temporally resolves multiple returns from each individual which show good correlation with size and orientation, and demonstrate that there exists more than one significant scattering feature in the animaL. Imaging technologies used to exactly measure the morphology of the scattering features of fish include very highresolution Phase Contrast X-rays (PCX) and Computerized Tomography (CT) scans, which are used for morphological evaluation and incorporation into the scattering modeL. Studies such as this one, which combine scattering models with high-resolution morphological information and high-quality laboratory data, are crucial to the quantitative use of acoustics in the ocean.

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Sonar oceanography

Ainslie

2009

Principles of Sonar Performance Modelling

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Measurement of the Dimensions of Fish to Facilitate Calculations of Echo-Strength in Acoustic Fish Detection

Cited by 15 publications

References 0 publications

Biological sound scattering studies

Biological sound scattering studies

Acoustic scattering by axisymmetric finite-length bodies with application to fish : measurement and modeling

Sonar oceanography

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