Modified Frequency-Bessel Transform Method for Dispersion Imaging of Rayleigh Wave from Ambient Seismic Noise

Abstract

Surface wave methods based on ambient noise have gained much attention from geophysical and civil engineering communities because of the limited application of traditional seismic surveys in highly populated urban areas. Higher modes information is important in dispersion curve inversion for shear-wave velocity structure. A method using the Frequency-Bessel (F-J) transform is for extracting the multimode dispersion curves from ambient seismic noise recordings. At high frequencies, the measured dispersion energy image by the F-J transform, however, would usually be polluted by a type of “crossed” artifacts. We proposed a modified frequency-Bessel (MFJ) transform by replacing the Bessel function in the F-J method with the Hankel function to attenuate the artifacts. A numerical simulation and a real-world example indicate the effectiveness of the proposed MFJ method in improving the accuracy of Rayleigh wave dispersion measurements, compared with the F-J method.