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Draganov, D.S. (author), Wapenaar, C.P.A. (author)
conference paper 2015
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Singh, S. (author), Snieder, R. (author), Behura, J. (author), van der Neut, J.R. (author), Wapenaar, C.P.A. (author), Slob, E.C. (author)
Recent work on retrieving the Green’s function with the Marchenko equation shows how these functions for a virtual source in the subsurface can be obtained from reflection data. The response to the virtual source is the Green’s function from the location of the virtual source to the surface. The Green’s function is retrieved using only the...
journal article 2015
document
Wapenaar, C.P.A. (author), Van der Neut, J.R. (author), Draganov, D.S. (author)
Under conditional circumstances, the correlation of noise at two receivers is approximately proportional to the Green’s function between these receivers. Hence, the correlation process turns one of the receivers into a virtual source, of which the response is observed by the other receiver. This principle, also known as ambient-noise...
conference paper 2015
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Van der Neut, J.R. (author), Wapenaar, C.P.A. (author), Thorbecke, J.W. (author), Slob, E.C. (author), Vasconcelos, I. (author)
In Marchenko imaging, wavefields are retrieved at specified focal points in the subsurface through an iterative scheme derived from the multidimensional Marchenko equation. The method requires seismic-reflection data at the earth’s surface (after free-surface multiple elimination) and an estimate of the direct wavefield from the surface to each...
journal article 2015
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Van der Neut, J.R. (author), Thorbecke, J.W. (author), Wapenaar, C.P.A. (author), Slob, E.C. (author)
Focusing functions are defined as wavefields that focus at a specified location in a heterogeneous subsurface. These functions can be directly related to Green's functions and hence they can be used for seismic imaging of complete wavefields, including not only primary reflections but all orders of internal multiples. Recently, it has been shown...
conference paper 2015
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Harmankaya, U. (author), Kaslilar, A. (author), Van Wijk, K. (author), Wapenaar, C.P.A. (author), Draganov, D.S. (author)
Inspired by a technique called seismic interferometry, we estimate the location of scatterers in a scaled model, where many near-surface scatterers are present. We isolate the scattered wavefield and evaluate correlation of scattered waves at different receiver locations. The cross-correlation eliminates the travel path between a source and a...
conference paper 2015
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Wapenaar, C.P.A. (author), Slob, E.C. (author)
Building on acoustic autofocusing in 1D media, we previously proposed acoustic Marchenko imaging for 1D and 3D media. Recently, the first steps have been set towards extending the single-sided Marchenko method to the elastodynamic situation. Here we discuss the extension of single-sided Marchenko focusing, Green's function retrieval and imaging...
conference paper 2015
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Van Dalen, K.N. (author), Mikesell, T.D. (author), Ruigrok, E.N. (author), Wapenaar, C.P.A. (author)
Retrieving virtual source surface waves from ambient seismic noise by cross correlation assumes, among others, that the noise field is equipartitioned and the medium is lossless. Violation of these assumptions reduces the accuracy of the retrieved waves. A point-spread function computed from the same ambient noise quantifies the associated...
journal article 2015
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Van der Neut, J.R. (author), Vasconcelos, I. (author), Wapenaar, C.P.A. (author)
Iterative substitution of the coupled Marchenko equations is a novel methodology to retrieve the Green's functions from a source or receiver array at an acquisition surface to an arbitrary location in an acoustic medium. The methodology requires as input the single-sided reflection response at the acquisition surface and an initial focusing...
journal article 2015
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Hartstra, I.E. (author), Wapenaar, C.P.A. (author)
We discuss a method to interferometrically retrieve the body wave reflection response from local high-frequency scattering coda wave fields with the purpose to obtain an input dataset suitable for the application of advanced exploration-type imaging methods
conference paper 2015
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Smets, P. (author), Evers, L.G. (author), Wapenaar, C.P.A. (author)
journal article 2014
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Slob, E.C. (author), Hunziker, J.W. (author), Thorbecke, J.W. (author), Wapenaar, C.P.A. (author)
conference paper 2014
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Wapenaar, C.P.A. (author)
In time-reversal acoustics, waves recorded at the boundary of a strongly scattering medium are sent back into the medium to focus at the original source position. This requires that the medium can be accessed from all sides. We discuss a focusing method for media that can be accessed from one side only.We show how complex focusing functions,...
journal article 2014
document
Wapenaar, C.P.A. (author)
In time-reversal acoustics, waves recorded at the boundary of a strongly scattering medium are sent back into the medium to focus at the original source position. This requires that the medium can be accessed from all sides. We discuss a focusing method for media that can be accessed from one side only. We show how complex focusing functions,...
journal article 2014
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Liu, Y. (author), Arntsen, B. (author), Wapenaar, C.P.A. (author), Van der Neut, J.R. (author)
The virtual source method has been applied successfully to retrieve the impulse response between pairs of receivers in the subsurface. This method is further improved by an updown separation prior to the crosscorrelation to suppress the reflections from the overburden and the free surface. In a reversed situation where the sources are in the...
conference paper 2014
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Boullenger, B. (author), Wapenaar, C.P.A. (author), Draganov, D.S. (author)
Seismic interferometry applied to surface reflection data (with source and receivers at the surface) allows to retrieve virtual-source gathers at the position of receivers, where no source was shot. As a result of the crosscorrelation of all primary and multiple reflections, the virtual-source gathers contain retrieved physical reflections as...
conference paper 2014
document
Van der Neut, J.R. (author), Wapenaar, C.P.A. (author), Thorbecke, J.W. (author), Vasconcelos, I. (author)
Recently, a novel iterative scheme was proposed to retrieve Green's functions in an unknown medium from its single-sided reflection response and an estimate of the propagation velocity. In Marchenko imaging, these Green's functions are used for seismic imaging with complete wavefields, including internal multiple reflections. In this way, common...
conference paper 2014
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Wapenaar, C.P.A. (author), Van der Neut, J.R. (author), Thorbecke, J.W. (author), Vasconcelos, I. (author), Van Manen, D.J. (author), Ravasi, M. (author)
Despite the close links between the fields of time-reversed acoustics, seismic interferometry and Marchenko imaging, a number of subtle differences exist. This paper reviews the various focusing conditions of these methods, the causality/acausality aspects of the corresponding focusing wavefields, and the requirements with respect to...
conference paper 2014
document
Singh, S. (author), Snieder, R. (author), Behura, J. (author), van der Neut, J.R. (author), Wapenaar, C.P.A. (author), Slob, E.C. (author)
Recent work on autofocusing with the Marchenko equation has shown how the Green's function for a virtual source in the subsurface can be obtained from reflection data. The response to the virtual source is the Green's function from the location of the virtual source to the surface. The Green's function is retrieved using only the reflection...
conference paper 2014
document
Fricke, J.T. (author), Evers, L.G. (author), Smets, P.S.M. (author), Wapenaar, C.P.A. (author), Simons, D.G. (author)
We present the results of infrasonic interferometry applied to microbaroms, obtained from ambient noise. For this purpose the “Large Aperture Infrasound Array” (LAIA) was used, which has been installed in the Netherlands. Preprocessing appeared to be an essential step in enhancing the microbarom signals from ambient noise that strongly...
journal article 2014
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