Quantifying Sediment Volume Inhomogeneity for Modeling High-Frequency Acoustic Backscatter

1999 ◽  
Author(s):  
Thomas Orsi ◽  
Dajun Tang ◽  
Anthony P. Lyons
Keyword(s):  
High Frequency ◽  
Acoustic Backscatter ◽  
Sediment Volume ◽  
Volume Inhomogeneity

scholarly journals Effects of Noise and Absorption on High Frequency Measurements of Acoustic-Backscatter from Fish

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Masahiko Furusawa
Keyword(s):  
Measurement Error ◽  
Environmental Conditions ◽  
High Frequency ◽  
Signal To Noise Ratio ◽  
Target Strength ◽  
Acoustic Backscatter ◽  
Signal To Noise ◽  
Absorption Coefficients ◽  
Frequency Measurements ◽  
Multiple Frequencies

Quantitative echosounders operating at multiple frequencies (e.g., 18, 38, 70, 120, 200, 333, and 710 kHz) are often used to observe fish and zooplankton and identify their species. At frequencies above 100 kHz, the absorption attenuation increases rapidly and decreases the signal-to-noise ratio (SNR). Also, incomplete compensation for the attenuation may result in measurement error. This paper addresses the effects of the attenuation and noise on high frequency measurements of acoustic backscatter from fish. It is shown that measurements of a fish with target strength of −40 dB at 200 m depth are limited by SNR to frequencies up to about 100 kHz. Above 100 kHz, absorption coefficients must be matched to local environmental conditions.

Temporal model of high‐frequency seafloor acoustic backscatter

1994 ◽  
Vol 96 (5) ◽  
pp. 3287-3287
Author(s):  
Christian de Moustier ◽  
Daniel Sternlicht
Keyword(s):  
High Frequency ◽  
Acoustic Backscatter ◽  
Temporal Model

scholarly journals High‐frequency acoustic backscatter sea surface

1984 ◽  
Vol 75 (S1) ◽  
pp. S31-S31
Author(s):  
W. I. Roderick ◽  
R. K. Dullea ◽  
J. B. Chester
Keyword(s):  
High Frequency ◽  
Sea Surface ◽  
Acoustic Backscatter

scholarly journals The dance of the nanobubbles: detecting acoustic backscatter from sub-micron bubbles using ultra-high frequency acoustic microscopy

Nanoscale ◽  
2020 ◽  
Vol 12 (41) ◽  
pp. 21420-21428
Author(s):  
Michael J. Moore ◽  
Filip Bodera ◽  
Christopher Hernandez ◽  
Niloufar Shirazi ◽  
Eric Abenojar ◽  
...  
Keyword(s):  
High Frequency ◽  
Acoustic Microscopy ◽  
Acoustic Backscatter ◽  
Agarose Gel ◽  
Acoustic Microscope ◽  
Ultra High Frequency

Detection of the motion of individual nanobubbles and microbubbles in an agarose gel using an ultra-high frequency acoustic microscope.

scholarly journals A Method for Estimating Dominant Acoustic Backscatter Mechanism of Water-Seabed Interface via Relative Entropy Estimation

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Bo Zou ◽  
Jingsheng Zhai ◽  
Jian Xu ◽  
Zhaoxing Li ◽  
Sunpei Gao
Keyword(s):  
Relative Entropy ◽  
Acoustic Scattering ◽  
Interface Roughness ◽  
Acoustic Backscatter ◽  
Bayesian Inversion ◽  
Observation Data ◽  
Fluid Approximation ◽  
Identification Scheme ◽  
Sediment Volume ◽  
Posterior Probability Density

It is important to distinguish the dominant mechanism of seabed acoustic scattering for the quantitative inversion of seabed parameters. An identification scheme is proposed based on Bayesian inversion with the relative entropy used to estimate dominant acoustic backscatter mechanism. DiffeRential Evolution Adaptive Metropolis is used to obtain samples from posterior probability density in Bayesian inversion. Three mechanisms for seabed scattering are considered: scattering from a rough water-seabed interface, scattering from volume heterogeneities, and mixed scattering from both interface roughness and volume heterogeneities. Roughness scattering and volume scattering are modelled based on Fluid Theories using Small-Slope Approximation and Small-Perturbation Fluid Approximation, respectively. The identification scheme is applied to three simulated observation data sets. The results indicate that the scheme is promising and appears capable of distinguishing sediment volume from interface roughness scattering and can correctly identify the dominant acoustic backscatter mechanism.

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