We evaluated a method for the simultaneous analysis of velocity and attenuation of multichannel surface wave data. It allowed us to estimate the phase velocity and attenuation curves using an array of receivers, possibly unevenly spaced, and a set of multiple shots at different locations. After reviewing the properties of surface waves in dissipative media, the estimation algorithm was evaluated. It was based on the estimation of the complex wavenumber of multiple normal modes. It can be considered as a highresolution subspace-based method able to deal with irregularly sampled multichannel-multishot data. The interference between multiple modes was considered without the need of a prior specific multimode Rayleigh spreading function, so that multiple modal attenuation curves can be extracted. The validity of the approach was tested using synthetic data, with small and large mode interference, as well as with multimode real data. The benefits and the robustness of the proposed method were particularly relevant with data with multiple modes. The possibility of considering multiple shot points into a receiver array allowed the increase of the modal resolution without increasing the receiver aperture, thus without compromising the lateral resolution. The estimation of the modal attenuation coefficient enabled the estimation of the subsurface material damping ratio, and the definition of a dissipative propagation model.
Various aspects of survey design have a profound impact on how noise appears on the coherent signal of interest, thus impacting conventional inversion methods in complex environments. We propose a multistage physics-driven prior-based processing technique that is versatile and can be used in a wide range of inversion-based processing applications such as source separation and/or interpolation for any acquisition environments (e.g., land, marine, and ocean-bottom nodes). The inversion-based multistage approach progressively builds the coherent signal model while eliminating the aliasing, blending, and background noise in a signal-safe manner. To stabilize the inversion process, we include physics-driven priors in the multiple stage process, which enhances the sparsity of the coherent signal in the transform domain. Results using real data from land and ocean-bottom node surveys validate the potential of the proposed approach to produce optimal processing results while dealing with the common geophysical challenges related to different seismic acquisitions.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.