Journal ArticleDOI
On the remote acoustic detection of suspended sediment at long wavelengths
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In this article, a linear relation between the time-averaged amplitude of the envelope of the backscattered acoustic pulse at 192 kHz and the square root of suspended sediment concentration in the 10 to 103 mg 1−1 range was found.Abstract:
Experimental results are presented which indicate a linear relation between the time-averaged amplitude of the envelope of the backscattered acoustic pulse at 192 kHz and the square root of suspended sediment concentration in the 10 to 103 mg 1−1 range. Particle sizes ranged from 2 to 140 μm. The measurements were made in a negatively buoyant, mine-tailing discharge plume in a submarine channel at depths of 60 to 90 m in Rupert Inlet, British Columbia. From the theory of acoustic backscatter from a solid elastic sphere in the Rayleigh region it is shown that if the pressure amplitude of the backscattered wave is Rayleigh distributed, then such a linear relation is to be expected. Expressions for the optimum acoustic frequency for the detection of dilute suspensions at a given range and for the minimum detectable concentration are obtained assuming a thermal noise background. The possibility that bubbles contribute to the backscatter is considered and found to be unlikely on the basis of probable bubble lifetimes.read more
Citations
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Journal ArticleDOI
Vertical Profiles of Suspended Sand Concentration and Size From Multifrequency Acoustic Backscatter
Alex E. Hay,Jinyu Sheng +1 more
TL;DR: In this paper, vertical profiles of suspended sand concentration and size were obtained from multifrequency acoustic profiling data collected in 1989 during a nearshore experiment at Stanhope Lane Beach, Prince Edward Island.
Journal ArticleDOI
Measuring flow velocity and sediment transport with an acoustic Doppler current profiler
TL;DR: An acoustic Doppler current profiler (aDcp) as mentioned in this paper measures three-dimensional velocity profiles within the water column using the doppler shift principle, whilst the bottom tracking function and acoustic backscatter can be used to measure bed load velocity and estimate suspended sediment concentration.
Journal ArticleDOI
An Examination of the Spherical Scatterer Approximation in Aqueous Suspensions of Sand
Jinyu Sheng,Alex E. Hay +1 more
TL;DR: In this article, the available data for scattered acoustic intensity and attenuation in dilute aqueous suspensions of sand are compared with theory, and a modified high-pass model provides a fit to the data that is as good as, or better than, the r...
BookDOI
Estuarine Cohesive Sediment Dynamics
TL;DR: A review of published literature and field observations of estuarine suspended sediment in the Chesapeake Bay region, indicate that sediment is resuspended in response to fluctuating energy over a wide range of time scales.
Journal ArticleDOI
Sound scattering from a particle‐laden, turbulent jet
TL;DR: In this paper, a free, turbulent water jet carrying solid particles in suspension was used to conduct multifrequency acoustic scattering experiments in the laboratory using a crossed-beam geometry, in which the axis of the jet was perpendicular, or nearly so, to the direction of the incident sound.
References
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Journal ArticleDOI
Acoustic Ambient Noise in the Ocean: Spectra and Sources
TL;DR: In this paper, the authors compared the results of recent ambient-noise investigations, after appropriate processing, on the basis of pressure spectra in the frequency band 1 cps to 20 kc.
Journal ArticleDOI
Sound Scattering by Solid Cylinders and Spheres
Abstract: The theory of the scattering of plane waves of sound by isotropic circular cylinders and spheres is extended to take into account the shear waves which can exist (in addition to compressional waves) in scatterers of solid material. The results can be expressed in terms of scattering functions already tabulated. Scattering patterns computed on the basis of the theory are shown to be in good agreement with experimental measurements of the distribution‐in‐angle of sound scattered in water by metal cylinders. Rapid changes with frequency in the distribution‐in‐angle of the scattered sound and in the total scattered energy are found to occur near frequencies of normal modes of free vibration of the scattering body.
Book
Submarine canyons and other sea valleys
TL;DR: A new book that many people really want to read will you be one of them? Of course, you should be as mentioned in this paper, even some people think that reading is a hard to do, you must be sure that you can do it.
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Vertical Profiles of Suspended Sand Concentration and Size From Multifrequency Acoustic Backscatter
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