Professor Boris Katsnelson from University of Haifa, Israel, visited the Institute of Acoustics (IOA) for half a month from November 4.  

Boris Katsnelson is a professor of the Physics Department, Voronezh State University, Russia and the School of Marine Sciences, University of Haifa, Israel. He has done some excellent works on wave propagation theory, oceanography, underwater acoustics, acoustic tomography, and mathematical physics. He has hundred seventy publications including two books such as Shallow water acoustics and Fundamentals of shallow water acoustics. Recently, his research interests focus on sound propagation in three dimensional ocean environments. 

Professor Boris Katsnelson is a visiting scientist of “CAS President’s International Fellowship Initiative”. During the visit at the IOA, he gave an academic lecture entitled "Sound fluctuations in the presence of nonlinear (intense) internal waves and estimation of parameters of shallow water waveguide". It was hosted by Professor ZHANG Renhe from the State Key Laboratory of Acoustics and more than fifty IOA staff and students attended it. 

In the lecture, on the base of theory of the sound field variability due to mode coupling, analysis of fluctuations of low frequency propagating in shallow water in the presence of nonlinear internal waves was carried out. And temporal fluctuation of the sound field for the long-time observation in the presence of the hydrodynamic perturbations (nonlinear internal waves) can give some information for the solution of inverse problem-estimation of properties of unperturbed waveguide, such as bottom parameters.        

Professor Boris Katsnelson also gave a series of lectures about the subject of shallow water acoustics, including “Sound field of the point source in a layered waveguide”, “Noise in shallow water”, “Sound field in shallow water waveguide with random inhomogeneities”, and “Horizontal refraction in shallow water”.  

Besides, Professor Boris Katsnelson discussed the collaboration of the NFSC-ISF program and the Joint Graduate Training Program with the State Key Laboratory of Acoustics.  

Professor Boris Katsnelson (right) and Professor LI Zhenglin (left) from IOA

(Resource: REN Yun from the State Key Laboratory of Acoustics)