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Anatoliy Ivakin

Senior Principal Physicist

Email

ani@apl.washington.edu

Phone

206-616-4808

Biosketch

Anatoliy Ivakin's research interests include wave propagation and scattering in continuous and discrete media with rough interfaces and volume heterogeneity, theoretical and numerical modeling of random processes and fields, signal processing and inversion techniques, environmental acoustics and applications to underwater reverberation and remote sensing, sea-bed and sea-ice characterization, marine ecology, as well as detection and assessment of oil, gas, and gas hydrates, and environmental monitoring and evaluation of risks related to offshore oil and gas exploration, production, and transportation.

Dr. Ivakin joined APL-UW as a Senior Physicist in 2001 and was elected to Fellowship in the Acoustical Society of America the same year.

Department Affiliation

Acoustics

Education

M.S. Physics, Moscow Institute of Physics and Technology, 1978

Ph.D. Physics and Mathematics, Andreev Acoustics Institute, Moscow, 1982

Publications

2000-present and while at APL-UW

A full-field perturbation approach to scattering and reverberation in range-dependent environments with rough interfaces

Ivakin, A., "A full-field perturbation approach to scattering and reverberation in range-dependent environments with rough interfaces," J. Acoust. Soc. Am., 140, 657-665, doi:10.1121/1.4959111, 2016.

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1 Jul 2016

A perturbation approach to roughness scattering and reverberation in range-dependent environments is developed treating each interface as a superposition of a smooth reference interface, which may include large-scale deterministic features (such as bathymetry changes), and small compared to the acoustic wavelength vertical deviations from this interface that are considered as random roughness perturbations. The reference interface is assumed to be smooth enough to allow analytic or numerical solution for the field in the vicinity of this interface that can then be used in perturbation theory. Expressions for both the reverberation field and average reverberation intensity in a general case of an arbitrary number of rough interfaces are obtained in a form convenient for numerical simulations. In the case of long-range ocean reverberation, several approximations for these expressions are developed, relevant to various environmental scenarios and different types of interfaces: sea-surface, water-sediment interface, buried sediment interfaces, and bottom basement. The results are presented in a simple form and provide a direct relationship of the reverberation intensity with three critical characteristics defined at each interface: (1) local spectrum of roughness, (2) local contrast of acoustic parameters, and (3) two-way full-field transmission intensity calculated taking into account only large-scale changes of the environment.

Modeling of Mid-Frequency Reverberation in Very Shallow Water: A Green's Function Approach and Application to TREX2013 Data Analysis

Ivakin, A.N., "Modeling of Mid-Frequency Reverberation in Very Shallow Water: A Green's Function Approach and Application to TREX2013 Data Analysis," Technical Report, APL-UW TR 1502, Applied Physics Laboratory, University of Washington, Seattle, September 2015, 30 pp.

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22 Sep 2015

The long-term goals of this research are to better understand and accurately model low- to mid-frequency reverberation in shallow water environments. Specific goals are to develop a model of reverberation for conditions (1–10 kHz, ~ 20 m water depth, ~ 10 km range) corresponding to the ONR Target and Reverberation Experiment performed in spring 2013 (TREX2013), develop a code and conduct computer simulations with environmental inputs typical for the chosen location, and apply this model to analysis of available TREX2013 data. This report presents a Green's function modeling approach that allows fast estimations of volume reverberation in complex shallow water environments. A simplified first-order version of the approach is considered to show how far-field scattering solutions obtained for free space can be incorporated into reverberation in complicated bounded, range-dependent, and stratified environments. A higher-order modification of this approach is considered as well, using a MFSB (Multiple Forward Single Backscatter) approximation. Application to TREX2013 reverberation data and tentative model–data comparisons are presented.

High-frequency acoustic backscattering from a sand sediment: Experiments and data/model comparisons

Hefner, B.T., A.N. Ivakin, and D.R. Jackson, "High-frequency acoustic backscattering from a sand sediment: Experiments and data/model comparisons," J. Acoust. Soc. Am., 132, 2092, doi:, 2012.

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1 Sep 2012

In the Spring of 2012, high-frequency backscattering from a sandy sediment was measured in the Gulf of Mexico at the site of the upcoming, ONR-sponsored reverberation experiment. The measurements were made using an array of sources and receivers that collected data from 200 to 500 kHz and that could be rotated such that the incident grazing angles varied from 10 to 50 degrees. This array was used previously to measure scattering from a sand/mud sediment during the Sediment Acoustics Experiment 2004 (SAX04). To support data/model comparisons, the seabed roughness, sediment shell content, sediment sound speed, and sediment attenuation were also measured. For scattering below the critical grazing angle, sediment roughness is found to be the dominant scattering mechanism while above the critical angle, roughness scattering underpredicts the measured scattering strength. To understand the scattering strength at high grazing angles, scattering from shells and shell hash is considered. The measured scattering strengths and environmental properties at the experiment site are also compared to those made during SAX04.

More Publications

Acoustics Air-Sea Interaction & Remote Sensing Center for Environmental & Information Systems Center for Industrial & Medical Ultrasound Electronic & Photonic Systems Ocean Engineering Ocean Physics Polar Science Center
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