Searched for: collection%3Air
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Wapenaar, C.P.A. (author), Brackenhoff, J.A. (author), Thorbecke, J.W. (author), van der Neut, J.R. (author), Slob, E.C. (author), Verschuur, D.J. (author)
A virtual acoustic source inside a medium can be created by emitting a time-reversed point-source response from the enclosing boundary into the medium. However, in many practical situations the medium can be accessed from one side only. In those cases the time-reversal approach is not exact. Here, we demonstrate the experimental design and...
journal article 2018
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Meles, G.A. (author), Wapenaar, C.P.A. (author), Thorbecke, J.W. (author)
Marchenko redatuming is a novel scheme used to retrieve up- and downgoing Green's functions in an unknown medium.Marchenko equations are based on reciprocity theorems and are derived on the assumption of the existence of functions exhibiting space-time focusing properties once injected in the subsurface. In contrast to interferometry but...
journal article 2018
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Wapenaar, C.P.A. (author), Staring, M. (author)
In seismic monitoring, one is usually interested in the response of a changing target zone, embedded in a static inhomogeneous medium. We introduce an efficient method that predicts reflection responses at the Earth's surface for different target-zone scenarios, from a single reflection response at the surface and a model of the changing...
journal article 2018
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Harmankaya, U (author), Kaslilar, A. (author), Wapenaar, C.P.A. (author), Draganov, D.S. (author)
Unexpected geological structures can cause safety and economic risks during underground excavation. Therefore, predicting possible geological threats while drilling a tunnel is important for operational safety and for preventing expensive standstills. Subsurface information for tunneling is provided by exploratory wells and by surface...
journal article 2018
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Hartstra, I.E. (author), Almagro Vidal, C. (author), Wapenaar, C.P.A. (author)
Virtual Green's functions obtained by seismic interferometry (SI) can provide valuable reflectivity data that can complement tomographic inversion schemes. However, virtual reflections are affected by illumination irregularities that are typical of earthquake-induced wavefields recorded by the receiver array. As a consequence, irregular...
journal article 2018
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Holicki, M.E. (author), Drijkoningen, G.G. (author), Wapenaar, C.P.A. (author)
Up–down wavefield decomposition is effectuated by a scaled addition or subtraction of the pressure and vertical particle velocity, generally on horizontal or vertical surfaces, and works well for data given on such surfaces. The method, however, is not applicable to decomposing a wavefield when it is given at one instance in time, i.e. on...
journal article 2018
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Almagro Vidal, C. (author), van der Neut, J.R. (author), Verdel, Arie (author), Hartstra, I.E. (author), Wapenaar, C.P.A. (author)
Passive seismic interferometry enables the estimation of the reflection response of the subsurface using passive receiver recordings at the surface from sources located deep in the Earth. Interferometric imaging makes use of this retrieved reflection response in order to study the subsurface. Successful interferometric imaging relies on the...
journal article 2018
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Staring, M. (author), Pereira, Roberto (author), Douma, Huub (author), van der Neut, J.R. (author), Wapenaar, C.P.A. (author)
We have developed an adaptive double-focusing method that is specifically designed for the field-data application of source-receiver Marchenko redatuming. Typically, the single-focusing Marchenko method is combined with a multidimensional deconvolution (MDD) to achieve redatuming. Our method replaces the MDD step by a second focusing step...
journal article 2018
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Cui, Tianci (author), Vasconcelos, Ivan (author), Manen, Dirk Jan Van (author), Wapenaar, C.P.A. (author)
Marchenko redatuming can retrieve the impulse response to a subsurface virtual source from the single-sided surface reflection data with limited knowledge of the medium. We illustrate the concepts and practical aspects of Marchenko redatuming on a simple 1D acoustic lossless medium in which the coupled Marchenko equations are exact. Defined...
journal article 2018
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Zhang, L. (author), Slob, E.C. (author), van der Neut, J.R. (author), Wapenaar, C.P.A. (author)
We have derived an improved reverse time migration (RTM) scheme to image the medium without artifacts arising from internal multiple reflections. This is based on a revised implementation of Marchenko redatuming using a new time-truncation operator. Because of the new truncation operator, we can use the time-reversed version of the standard...
journal article 2018
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Thorbecke, J.W. (author), Slob, E.C. (author), Brackenhoff, J.A. (author), van der Neut, J.R. (author), Wapenaar, C.P.A. (author)
The Marchenko method makes it possible to compute subsurface-to-surface Green's functions from reflection measurements at the surface. Applications of the Marchenko method have already been discussed in many papers, but its implementation aspects have not yet been discussed in detail. Solving the Marchenko equation is an inverse problem. The...
journal article 2017
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Liu, Y. (author), Landrø, Martin (author), Arntsen, Børge (author), van der Neut, J.R. (author), Wapenaar, C.P.A. (author)
For a robust way of estimating time shifts near horizontal boreholes, we have developed a method for separating the reflection responses above and below a horizontal borehole. Together with the surface reflection data, the method uses the direct arrivals from borehole data in the Marchenko method. The first step is to retrieve the focusing...
journal article 2017
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Slob, E.C. (author), Wapenaar, C.P.A. (author)
We present a three-dimensional scheme that can be used to compute the electromagnetic impulse response between any two subsurface points from surface reflection data measured at a single surface of a lossless medium. The scheme first computes a virtual vertical radar profile using the Marchenko scheme from which focusing wavefields are...
conference paper 2017
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van der Neut, J.R. (author), Johnson, Jami L. (author), van Wijk, K. (author), Singh, S. (author), Slob, E.C. (author), Wapenaar, C.P.A. (author)
From acoustics to medical imaging and seismology, one strives to make inferences about the structure of complex media from acoustic wave observations. This study proposes a solution that is derived from the multidimensional Marchenko equation, to learn about the acoustic source distribution inside a volume, given a set of observations outside...
journal article 2017
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Wapenaar, C.P.A. (author)
journal article 2017
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Hartstra, I.E. (author), Almagro Vidal, C. (author), Wapenaar, C.P.A. (author)
Our objective is to complement lithospheric seismic tomography with an interferometric method to retrieve high-resolution reflectivity images from local earthquake recordings. The disadvantage of using local earthquakes for the retrieval of reflected body-waves is their usual sparse distribution. We propose an alternative formulation of passive...
journal article 2017
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Weemstra, C. (author), Draganov, D.S. (author), Ruigrok, E.N. (author), Hunziker, J.W. (author), Gomez, Martin (author), Wapenaar, C.P.A. (author)
Obtaining new seismic responses from existing recordings is generally referred to as seismic interferometry (SI). Conventionally, the SI responses are retrieved by simple crosscorrelation of recordings made by separate receivers: one of the receivers acts as a ‘virtual source’ whose response is retrieved at the other receivers.When SI is applied...
journal article 2017
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Wapenaar, C.P.A. (author), Slob, E.C. (author)
In a time-lapse experiment, changes in a reservoir cause changes in the reflection response. We discuss a method which predicts these changes from the baseline survey and a model of the changed reservoir. This method, which takes all multiple
scattering into account, is significantly more efficient than modeling the response of the entire...
conference paper 2017
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Holicki, M.E. (author), Drijkoningen, G.G. (author), Wapenaar, C.P.A. (author)
We propose a novel directional decomposition operator for wavefield snapshots in heterogeneous-velocity media. The proposed operator demonstrates the link between the amplitude of pressure and particlevelocity plane waves in the wavenumber domain. The proposed operator requires two spatial Fourier transforms (one forward and one backward) per...
conference paper 2017
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Wapenaar, C.P.A. (author), Reinicke Urruticoechea, C. (author)
The homogeneous Green’s function is the Green’s function minus its timereversal. Many wavefield imaging applications make use of the homogeneous Green’s function in form of a closed boundary integral. Wapenaar et al. (2016a) derived an accurate single-sided homogeneous Green’s function representation that only requires sources/receivers on an...
conference paper 2017
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