Study of interface wave generation and shear wave velocity estimation.

Abstract

Estimation of the shear wave velocity profile versus depth and shear wave attenuation in the upper sediment layers has been an important research topic in underwater acoustics. The shear wave velocity profile is insensitive to hydrophone data measured in water column, while dispersion of the interface wave propagating along the water and sea bottom boundary (the Scholte wave) is closely related to shear wave velocity variation with depth in the upper sediment layers. However, due to the exponential decay of the amplitude of the interface waves, there may be no interface waves generated and recorded in a conventional underwater experiment configuration where the sources and receivers (vertical and/or horizontal hydrophone array) are located in the water column with distance (measured by wavelength of the interface wave) away from water bottom interface. In this paper the conditions in which interface waves can be generated, recorded, and visualized are studied by numerical experiments in the underwater environment. The conditions include source strength, frequency band, source–receiver configuration, and signal‐to‐noise ratio, etc. Examples are given for estimating of shear wave velocity profile with depth by inverting dispersion curves of recorded interface waves in real data. [Work supported by NFR under Contract No. 186923/I30.]