A method for single-hydrophone geoacoustic inversion based on the modal group velocities estimation: Application to a waveguide with inhomogeneous bottom relief

A Volunteer Computing Project for Solving Geoacoustic Inversion Problems

“…The dispersion-based technique for the geoacoustic waveguide parameters estimation [9] introduced by J. Bonnel and his colleagues several years ago is currently a very dynamic field of research in underwater acoustics [8,10,23,25]. In this technique, the dispersion data is used as an input of the inversion algorithm.…”

“…. M, where τm(f ) denotes the arrival time of m-th modal component [19,23] of a pulse acoustical signal as a function of frequency f (M is the total number of modes that can be filtered from the data). The curves t = τm(f ) in the two-dimensional time-frequency space are called dispersion curves [20].…”

“…Some interesting recent results [25] also indicate that single-hydrophone dispersion-based inversion method outlined in [9] can be used for the estimation of a sound-speed profile in a shallow-water waveguide. The implementation of this method in practice can be thought of as a solution of a minimization problem in a (very large) discrete search space [26], and every evaluation of the cost function requires numerous solutions of an acoustic spectral problem [23,26]. Thus, the whole computational burden can be easily divided into a large number of relatively simple independent tasks, offering many opportunities for the application of parallel computing.…”

“…In Section 2 we outline the dispersion-based geoacoustic inversion scheme following [8,9,23,26]. The synthetic acoustic data used in our work is discussed in Section 3.…”

“…While previously the data for the geoacoustic inversion was mostly obtained using expensive receiver arrays, recently it was shown that a single-hydrophone recording of a broadband pulse signal can be also successfully used for estimating the acoustical parameters of sea bottom [8][9][10]. Due to the lack of the spatial diversity in single-hydrophone measurements, the inversion procedure in this case relies on the so-called waveguide dispersion, i.e., the dependence of arrival times on frequency and mode number (see details, e.g., in [9,23]). Some interesting recent results [25] also indicate that single-hydrophone dispersion-based inversion method outlined in [9] can be used for the estimation of a sound-speed profile in a shallow-water waveguide.…”