Estimation of surface-wave group velocity using slant stack in the generalized S-transform domain

Geophysics ◽  
2015 ◽  
Vol 80 (4) ◽  
pp. EN83-EN92 ◽  
Author(s):  
Roohollah Askari ◽  
S. Hossein Hejazi
Keyword(s):  
Surface Wave ◽  
Group Velocity ◽  
Transform Domain ◽  
Wave Group ◽  
S Transform ◽  
Generalized S Transform

Sparsity-promoting method to estimate the dispersion curve of surface-wave group velocity

Geophysics ◽  
2019 ◽  
Vol 84 (1) ◽  
pp. V33-V43 ◽  
Author(s):  
Reza Dokht Dolatabadi Esfahani ◽  
Roohollah Askari ◽  
Ali Gholami
Keyword(s):  
Surface Wave ◽  
Group Velocity ◽  
Energy Concentration ◽  
Wave Group ◽  
Velocity Range ◽  
S Wave ◽  
New Approach ◽  
Time Frequency ◽  
Gaussian Window ◽  
S Transform

Group velocity is an important characteristic of surface wave that is defined as the velocity of an envelope of frequencies. Although many studies have shown the promises of analyzing the group velocity to obtain subsurface S-wave velocity, the estimation of the group velocity is not straightforward due to the uncertainties of selecting an optimum envelope of frequencies. Conventional transformations or filtering algorithms used to define an optimum envelope usually give reasonable results just for a narrow frequency or velocity range. We introduced a new approach for the estimation of the group velocity using the sparse S transform (SST) and sparse linear Radon transform (SLRT). In SST, the width of the Gaussian window is optimally calculated by energy concentration to eliminate energy smearing in the time-frequency (TF) domain, and then the sparsity is applied to enhance the TF resolution. Compared with conventional methods for the estimation of the group velocity based on the generalized S transforms, SST does not require any adjustment to the Gaussian window and yields accurate estimates of the group velocity. We apply SST to each seismic trace of a seismic shot record to obtain a 3D cube of frequency, time, and offset. For any frequency, we obtain a common frequency gather of time and offset to which we apply SLRT to obtain the group velocity of the surface wave. Our approach is robust at calculating high-resolution distinguishable dispersion curves of the group velocity in particular when data are extremely sparse.

Application of Conformal Mapping in Regional Surface Wave Group Velocity Inversion

2001 ◽  
Vol 44 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Liang-Bao ZHU ◽  
Qing XU ◽  
Xiao-Fei CHEN
Keyword(s):  
Surface Wave ◽  
Conformal Mapping ◽  
Group Velocity ◽  
Wave Group ◽  
Velocity Inversion

scholarly journals Surface wave group velocity in the Osaka sedimentary basin, Japan, estimated using ambient noise cross-correlation functions

2017 ◽  
Vol 69 (1) ◽  
Author(s):  
Kimiyuki Asano ◽  
Tomotaka Iwata ◽  
Haruko Sekiguchi ◽  
Kazuhiro Somei ◽  
Ken Miyakoshi ◽  
...  
Keyword(s):  
Surface Wave ◽  
Group Velocity ◽  
Correlation Functions ◽  
Ambient Noise ◽  
Cross Correlation ◽  
Sedimentary Basin ◽  
Wave Group ◽  
Noise Cross Correlation

scholarly journals Estimation of Surface Wave Group Velocity beneath the Chukyo Area, Japan

2014 ◽  
Vol 66 (4) ◽  
pp. 127-145 ◽  
Author(s):  
Takumi HAYASHIDA ◽  
Masayuki YOSHIMI ◽  
Haruo HORIKAWA
Keyword(s):  
Surface Wave ◽  
Group Velocity ◽  
Wave Group

Surface‐wave group‐velocity tomography for shallow structures at a waste site

1999 ◽  
Author(s):  
Leland Timothy Long ◽  
Argun Kocaoglu ◽  
William E. Doll ◽  
Xiuqi Chen ◽  
Jeffrey Martin
Keyword(s):  
Surface Wave ◽  
Group Velocity ◽  
Wave Group ◽  
Waste Site ◽  
Velocity Tomography

scholarly journals A MATLAB Package for Calculating Partial Derivatives of Surface-Wave Dispersion Curves by a Reduced Delta Matrix Method

2019 ◽  
Vol 9 (23) ◽  
pp. 5214 ◽  
Author(s):  
Wu ◽  
Wang ◽  
Su ◽  
Zhang
Keyword(s):  
Surface Wave ◽  
Group Velocity ◽  
Love Wave ◽  
Wave Dispersion ◽  
Dispersion Curves ◽  
Wave Group ◽  
Surface Wave Dispersion ◽  
Partial Derivatives ◽  
Matlab Package ◽  
Derivatives Of

Various surface-wave exploration methods have become increasingly important tools in investigating the properties of subsurface structures. Inversion of the experimental dispersion curves is generally an indispensable component of these methods. Accurate and reliable calculation of partial derivatives of surface-wave dispersion curves with respect to parameters of subsurface layers is critical to the success of these approaches if the linearized inversion strategies are adopted. Here we present an open-source MATLAB package, named SWPD (Surface Wave Partial Derivative), for modeling surface-wave (both Rayleigh- and Love-wave) dispersion curves (both phase and group velocity) and particularly for computing their partial derivatives with high precision. The package is able to compute partial derivatives of phase velocity and of Love-wave group velocity analytically based on the combined use of the reduced delta matrix theory and the implicit function theorem. For partial derivatives of Rayleigh-wave group velocity, a hemi-analytical method is presented, which analytically calculates all the first-order partial differentiations and approximates the mixed second-order partial differentiation term with a central difference scheme. We provide examples to demonstrate the effectiveness of this package, and demo scripts are also provided for users to reproduce all results of this paper and thus to become familiar with the package as quickly as possible.

Surface-Wave Group-Velocity Tomography for Shallow Structures

2001 ◽  
Vol 6 (2) ◽  
pp. 71-81 ◽  
Author(s):  
Leland Timothy Long ◽  
Argun H. Kocaoglu
Keyword(s):  
Surface Wave ◽  
Group Velocity ◽  
Wave Group ◽  
Velocity Tomography
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