Frequency-dependent spherical-wave reflection coefficient inversion in acoustic media: Theory to practice

Abstract

<jats:p> As an approximation of the spherical-wave reflection coefficient (SRC), the plane-wave reflection coefficient does not fully describe the reflection phenomenon of a seismic wave generated by a point source. The applications of SRC to improve analyses of seismic data have also been studied. However, most of the studies focus on the time-domain SRC and its benefit to using the long-offset information instead of the dependency of SRC on frequency. Consequently, we have investigated and accounted for the frequency-dependent spherical-wave reflection coefficient (FSRC) and analyzed the feasibility of this type of inversion. Our inversion strategy requires a single incident angle using reflection data for inverting the density and velocity ratios, which is distinctly different from conventional inversion methods using amplitude variation with offset. Hence, this investigation provides an alternative approach for estimating media properties in some contexts, especially when the range of aperture of the reflection angles is limited. We apply the FSRC theory to the inversion of noisy synthetic and field data using a heuristic algorithm. The multirealization results of the inversion strategy are consistent with the feasibility analysis and demonstrate the potential of the outlined method for practical application. </jats:p>

Study on the effect of different angles on the propagation characteristics of acoustic emission signals in wood

“…When the external force acts on the surface of the specimen, the elastic wave diffuses in the form of spherical wave in the specimen, causing vibration of each particle. 38 Thus, resulting in displacement signals, which can be collected by the AE sensor. The specimen thickness used in this experiment is only 30 mm, and the sensors were arranged on a narrow surface, as shown in Figure 1 .…”

Amplitude and phase changes for reflected and transmitted waves from a curved interface in anisotropic media

“…Harrison & Nielsen (2004) have shown that plane-wave reflection coefficients and spherical-wave reflection coefficients are related by a Hankel transform. AVO and data inversion using spherical-wave reflection coefficients have been demonstrated successful (Alhussain et al, 2008;Zhu & McMechan, 2015;Yan et al, 2020). However, it has to be remembered that, although they are largely used in common AVO/AVA studies, plane-wave reflection coefficients and spherical-wave reflection coefficients are strictly valid only for plane reflectors.…”