 Dr. Andrei Lunkov, Prokhorov General Physics Institute RAS, Russia
Personal profile: Head of laboratory / Associate professor, Prokhorov General Physics Institute RAS, Room 201, Building 1, 38 Vavilov Street, Moscow 119991, Russia
Dr. Andrey Lunkov is a head of hydrophysics laboratory at Prokhorov General Physics Institute of the Russian Academy of Sciences (GPI RAS), Moscow. He is also an associate professor at Bauman Moscow State Technical University (BMSTU). Andrey Lunkov received the B.S. and M.S. degrees in technical physics from BMSTU in 2007 and 2009, respectively, and Ph.D. degree in acoustics from GPI RAS in 2012. His current research interests include broadband sound propagation modeling in range and azimuth dependent shallow-water waveguides, acoustics of gassy and water-like sediments, acoustical limnology, and acoustics of arctic environments. He is an author of more than 50 peer reviewed papers.
Presentation title: Broadband sound propagation in shallow water with local inhomogeneities: Theory, modeling, and applications
Abstract: A coupled normal-mode theory is employed to study low-frequency (< 1 kHz) broadband sound propagation in a range-dependent shallow water waveguide with different types of local inhomogeneities (strong scatterers) and background inhomogeneities (weak scatterers). Analytical expressions are derived for the frequency dependence of normal mode amplitudes. The presence of a local inhomogeneity leads to the mode coupling, which causes oscillations in the frequency spectrum of modes. The period of oscillations is related to the distance between a sound source and an inhomogeneity. Numerical modeling is carried out for the following types of inhomogeneities: underwater ridge, internal solitary wave, ice keel, and sediment structure feature. A method for remote sensing of local homogeneities is proposed based on the frequency dependence of the first normal mode amplitude and its cepstral analysis. The method can be implemented with a single wideband sound source and a vertical receiving array for mode selection. Also, the vertical array can be replaced by a single hydrophone if warping transform is, and the hydrophone is positioned at an appropriate depth. The stability of the remote sensing method is tested numerically in the presence of several strong scatterers and additional disturbances: bottom slope, background internal waves, wind surface waves, bottom roughness. [The work was supported by the Russian Science Foundation, project No. 22-72-10121].
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