Abstract:
In order to enhance the realization and application of the ice-guided waves, this study conducted ice-guided waves excitation experiments using triaxial geophones and hammered sound sources during the ice-covered period of Qinghai Lake. The elliptical polarization and directional characteristics are described in detail by theoretical derivation, simulation analysis and experimental verification. The results of research indicate that within the ice layer, the vibrational particles of the ice-guided waves, which have an imaginary part of the wavenumber close to zero and can propagate over long distances, undergo elliptical polarization motion on the upper surface of the ice layer. Moreover, the vibrational particles of the M1 mode ice-guided waves always rotate counterclockwise relative to the direction of sound wave propagation, while those of the M2 mode rotate clockwise, demonstrating a distinct directional characteristic. It is no doubt that the elliptical polarization and directional characteristics of the particle motion trajectories of ice-guided waves will provide a method basis for the estimation of the bearing of sound source.