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Journal ArticleDOI

Broadband acoustic backscatter and high‐resolution morphology of fish: Measurement and modeling

02 Aug 2004-Journal of the Acoustical Society of America (Acoustical Society of America)-Vol. 116, Iss: 2, pp 747-761
TL;DR: Comparisons between the scattering predictions and data demonstrate the utility of the CT scan imagery for use in scattering models, as it provided a means for rapidly and noninvasively measuring the fish morphology in three dimensions and at high resolution.
Abstract: Remote detection and classification of marine organisms require careful acoustic backscattering measurements and acoustic scattering models that adequately incorporate morphology. A study has been conducted on alewife (Alosa pseudoharengus), a swimbladder‐bearing fish, which incorporated broadband (40–95 kHz) acoustic measurements, high‐resolution imaging of fish morphology, and associated scattering modeling using the images. Live, adult alewife were insonified while being rotated in 1‐deg increments of orientation angle in two planes of rotation (lateral and dorsal/ventral). These data provide orientation dependence of the scattering over a continuous band of frequencies, and identification of the dominant scattering features of the fish. X‐ray and CT scan images of the swimbladder were digitized and incorporated into the Kirchhoff‐Ray mode (KRM) model [Clay and Horne, J. Acoust. Soc. Am. 96, 1661–1668 (1994)] and the Fourier matching method (FMM), which has recently been extended to finite‐length bodies of rotation [Reeder and Stanton, J. Acoust. Soc. Am. (2004), in press]. The CT scan imagery provides rapid, noninvasive, high‐resolution morphological measurements in three dimensions. The potential of the new FMM formulation is demonstrated, which is a versatile approach, valid over a wide range of shapes, all frequencies and all angles of orientation. [Work supported by ONR and NOAA.]
Citations
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Journal ArticleDOI
TL;DR: This study presents a new probabilistic procedure that allows for real-time analysis of the response of the immune system to infectious diseases such as diarrhoea and septicaemia in Response to infectious disease.
Abstract: © 2010 The Authors. This article is distributed under the terms of the Creative Commons Attribution-Noncommercial License. The definitive version was published in ICES Journal of Marine Science: Journal du Conseil 67 (2010): 365-378, doi:10.1093/icesjms/fsp262.

119 citations


Cites background from "Broadband acoustic backscatter and ..."

  • ...With higher range resolution in this third channel, not only are the fish or features of the aggregation of fish resolved better, but there is potential for tilt-angle distribution to be inferred and for anatomical parts of the fish to be resolved (Stanton et al., 2003; Reeder et al., 2004)....

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  • ...…one broadband commercial echosounder for studying fish and zooplankton in the ocean (Ehrenberg and Torkelson, 2000; Ross and Lawson, 2009), and various laboratory applications with zooplankton, fish, and squid (Chu and Stanton, 1998; Reeder et al., 2004; Au and Benoit-Bird, 2008; Lee et al., 2009)....

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  • ...This type of processing is prevalent throughout radar and sonar applications, including one narrowband and one broadband commercial echosounder for studying fish and zooplankton in the ocean (Ehrenberg and Torkelson, 2000; Ross and Lawson, 2009), and various laboratory applications with zooplankton, fish, and squid (Chu and Stanton, 1998; Reeder et al., 2004; Au and Benoit-Bird, 2008; Lee et al., 2009)....

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Journal Article
TL;DR: Stanton et al. as discussed by the authors investigated the acoustic scattering properties of live individual zooplankton from several gross anatomical groups and found that the material type of each group strongly affects both the overall echo level and pattern of the target strength versus frequency plots.
Abstract: The acoustic scattering properties of live individual zooplankton from several gross anatomical groups have been investigated. The groups involve (1) euphausiids (Meganyctiphanes norvegica) whose bodies behave acoustically as a fluid material, (2) gastropods (Limacina retroversa) whose bodies include a hard elastic shell, and (3) siphonophores (Agalma okeni or elegans and Nanomia cara) whose bodies contain a gas inclusion (pneumatophore). The animals were collected from ocean waters off New England (Slope Water, Georges Bank, and the Gulf of Maine). The scattering properties were measured over parts or all of the frequency range 50 kHz to 1 MHz in a laboratory-style pulse-echo setup in a large tank at sea using live fresh specimens. Individual echoes as well as averages and ping-to-ping fluctuations of repeated echoes were studied. The material type of each group is shown to strongly affect both the overall echo level and pattern of the target strength versus frequency plots. In this first article of a two-part series, the dominant scattering mechanisms of the three animal types are determined principally by examining the structure of both the frequency spectra of individual broadband echoes and the compressed pulse (time series) output. Other information is also used involving the effect on overall levels due to (1) animal orientation and (2) tissue in animals having a gas inclusion (siphonophores). The results of this first paper show that (1) the euphausiids behave as weakly scattering fluid bodies and there are major contributions from at least two parts of the body to the echo (the number of contributions depends upon angle of orientation and shape), (2) the gastropods produce echoes from the front interface and possibly from a slow-traveling circumferential (Lamb) wave, and (3) the gas inclusion of the siphonophore dominates the echoes, but the tissue plays a role in the scattering and is especially important when analyzing echoes from individual animals on a ping-by-ping basis. The results of this paper serve as the basis for the development of acoustic scattering models in the companion paper [Stanton et al., J. Acoust. Soc. Am. 103, 236-253 (1998)].

98 citations

Journal ArticleDOI
TL;DR: In this article, acoustic surveys have been conducted on Georges Bank from 1998 to present to estimate Atlantic herring (Clupea harengus) population abundance, with a 12 or 18, 38, and 38-person survey.
Abstract: Acoustic surveys have been conducted on Georges Bank from 1998 to present to estimate Atlantic herring (Clupea harengus) population abundance. Acoustic data were collected with a 12 or 18, 38, and ...

84 citations


Cites methods from "Broadband acoustic backscatter and ..."

  • ...Broadband methods have been used to measure spectral responses from individuals (Kjærgaard et al. 1990; Reeder et al. 2004), compare spectra among different species (Simmonds and Armstrong 1990), and differentiate species using neural networks (Simmonds et al....

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Journal ArticleDOI
TL;DR: There are sufficient acoustic cues available to discriminate between the four species of fish based on the echoes received, independent of aspect angle, according to the echoes measured using simulated biosonar signals from Atlantic bottlenose dolphin and harbor porpoise.
Abstract: The biosonar system of dolphins and porpoises has been studied for about 5 decades and much has been learned [Au, W. W. L. (1993). The Sonar of Dolphins (Springer, New York)]. Most experiments have involved human-made targets; little is known about odontocetes' echolocation of prey. To address this issue, acoustic backscatter from Atlantic cod (Gadus morhua), gray mullet (Chelon labrosus), pollack, (Pollachius pollachius), and sea bass (Dicentrarchus labrax) was measured using simulated biosonar signals of the Atlantic bottlenose dolphin and harbor porpoise. The fish specimens were rotated so that the effects of the fish orientation on the echoes could be determined. Echoes had the highest amplitude and simplest structure when the incident angle was perpendicular to the longitudinal axis of the fish. The complexity of the echoes increased as the aspect angle of the fish moved away from the normal aspect. The echoes in both the time and frequency domains were easily distinguishable among the four species of fish and were generally consistent within species. A cochlear model consisting of a bank of band-passed filters was also used to analyze the echoes. The overall results suggest that there are sufficient acoustic cues available to discriminate between the four species of fish based on the echoes received, independent of aspect angle.

52 citations

Journal ArticleDOI
TL;DR: Analytical and numerical scattering models with accompanying digital representations are used increasingly to predict acoustic backscatter by fish and zooplankton in research and ecosystem monitoring applications and, in certain cases, outperformed the numerical models under conditions where the numerical model did not converge.
Abstract: Analytical and numerical scattering models with accompanying digital representations are used increasingly to predict acoustic backscatter by fish and zooplankton in research and ecosystem monitoring applications. Ten such models were applied to targets with simple geometric shapes and parameterized (e.g., size and material properties) to represent biological organisms such as zooplankton and fish, and their predictions of acoustic backscatter were compared to those from exact or approximate analytical models, i.e., benchmarks. These comparisons were made for a sphere, spherical shell, prolate spheroid, and finite cylinder, each with homogeneous composition. For each shape, four target boundary conditions were considered: rigid-fixed, pressure-release, gas-filled, and weakly scattering. Target strength (dB re 1 m(2)) was calculated as a function of insonifying frequency (f = 12 to 400 kHz) and angle of incidence (θ = 0° to 90°). In general, the numerical models (i.e., boundary- and finite-element) matched the benchmarks over the full range of simulation parameters. While inherent errors associated with the approximate analytical models were illustrated, so were the advantages as they are computationally efficient and in certain cases, outperformed the numerical models under conditions where the numerical models did not converge.

50 citations


Cites background from "Broadband acoustic backscatter and ..."

  • ...…from simple geometric shapes such as spheres, cylinders, and prolate spheroids (Anderson, 1950; Jech et al., 1995), to more accurate representations of fish anatomy (Clay and Horne, 1994; Reeder et al., 2004), zooplankton anatomy (Chu et al., 1993), and cephalopod anatomy (Lee et al., 2012)....

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References
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Book
01 Jan 1975

3,596 citations

Journal ArticleDOI
01 Nov 1996-Nature
TL;DR: In this paper, a simplified scheme for phase-contrast imaging based on an X-ray source having high spatial (but essentially no chromatic) coherence is presented. But the method is not suitable for large areas of irradiation, and it can operate with a lower absorbed dose than traditional Xray imaging techniques, and should find broad application in clinical, biological and industrial settings.
Abstract: IN conventional radiography, X-rays which pass through an object along different paths are differentially absorbed, and the intensity pattern of the emerging beam records the distribution of absorbing materials within the sample. An alternative approach is phase-contrast radiography, which instead records variations of the phase of the emerging radiation. Such an approach offers improved contrast sensitivity, especially when imaging weakly absorbing samples. Unfortunately, current phase-contrast imaging techniques1–11 generally require highly monochromatic plane-wave radiation and sophisticated X-ray optics, so their use is greatly restricted. Here we describe and demonstrate a simplified scheme for phase-contrast imaging based on an X-ray source having high spatial (but essentially no chromatic) coherence. The method is compatible with conventional polychromatic micro-focus X-ray tube sources, is well suited to large areas of irradiation, can operate with a lower absorbed dose than traditional X-ray imaging techniques, and should find broad application in clinical, biological and industrial settings.

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G. Turin1
TL;DR: In a tutorial exposition, the following topics are discussed: definition of a matched filter; where matched filters arise; properties of matched filters; matched-filter synthesis and signal specification; some forms of matched filter.
Abstract: In a tutorial exposition, the following topics are discussed: definition of a matched filter; where matched filters arise; properties of matched filters; matched-filter synthesis and signal specification; some forms of matched filters.

1,138 citations

Book
30 Oct 1997
TL;DR: The fundamental principles of underwater sound propagation are described in this paper, which is an authoritative reference for specialists in acoustics, oceanography, marine biology, and related fields, and also encourages a new generation of scientists, engineers and entrepreneurs to apply the modern methods of acoustical physics to probe the unknown sea.
Abstract: Fundamentals of Acoustical Oceanography an important reference for specialists in acoustics, oceanography, marine biology, and related fields. This book also encourages a new generation of scientists, engineers, and entrepreneurs to apply the modern methods of acoustical physics to probe the unknown sea. The book is an authoritative, modern text with examples and exercises. It contains techniques to solve the direct problems, solutions of inverse problems, and an extensive bibliography from the earliest use of sound in the sea to present references. The book provides background to measure ocean parameters and processes, find life and objects in the sea, communicate underwater, and survey the boundaries of the sea. Fundamentals of Acoustical Oceanography explains principles of underwater sound propagation, and describes how both actively probing sonars and passively listening hydrophones can reveal what the eye cannot see over vast ranges of the turbid ocean. This book demonstrates how to use acoustical remote sensing, variations in sound transmission, in situ acoustical measurements, and computer and laboratory models to identify the physical and biological parameters and processes in the sea.

660 citations


"Broadband acoustic backscatter and ..." refers background in this paper

  • ...Acoustically surveying the organisms could avoid these problems, particularly in the case of large-scale synoptic surveys that require high-resolution data (Gunderson, 1993; Medwin and Clay, 1998)....

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Journal ArticleDOI
TL;DR: In this paper, in situ measurements of fish target strength are selected for use in echo integrator surveys at 38 kHz, and the results are expressed through equations in which the mean target strength TS is regressed on the mean fish length l in centimeters.
Abstract: In situ measurements of fish target strength are selected for use in echo integrator surveys at 38 kHz. The results are expressed through equations in which the mean target strength TS is regressed on the mean fish length l in centimeters. For physoclists, TS=20 log l−67.4, and for clupeoids, TS=20 log l−71.9. These equations are supported by independent measurements on tethered, caged, and freely aggregating fish and by theoretical computations based on the swimbladder form. Causes of data variability are attributed to differences in species, behavior, and, possibly, swimbladder state.

419 citations


"Broadband acoustic backscatter and ..." refers background in this paper

  • ...Attempts have been made to empirically quantify the relationship between echo amplitude and actual fish length (Love, 1977; Foote, 1987)....

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