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Wapenaar, C.P.A. (author), van der Neut, J.R. (author), Thorbecke, J.W. (author), Slob, E.C. (author), Singh, Satyan (author)The homogeneous Green’s function (i.e., the Green’s function and its time-reversed counterpart) plays an important role in optical, acoustic and seismic holography, in inverse scattering methods, in the field of time-reversal acoustics, in reversetime migration and in seismic interferometry. Starting with the classical closed-boundary...conference paper 2016
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Wilding, D. (author), Pozzi, P. (author), Soloviev, O.A. (author), Vdovin, Gleb (author), Verhaegen, M.H.G. (author)Aberrations, scattering and absorption degrade the performance light-sheet fluorescence microscopes (LSFM). An adaptive optics system to correct for these artefacts and to optimize the light-sheet illumination is presented. This system allows a higher axial resolution to be recovered over the field-of-view of the detection objective. It is...conference paper 2016
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de Ridder, Sjoerd (author), van der Neut, J.R. (author), Curtis, A (author), Wapenaar, C.P.A. (author)Recently, a novel method to redatum the wavefield in the sub-surface from a reflection response measured at the surface has gained interest for imaging primaries in the presence of strong internal multiples. A prerequisite for the algorithm is an accurate and correct estimate of the direct-wave Green's function. However, usually we use an...conference paper 2016
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Kumar, A. (author)A seismic survey should be designed such that imaging of the acquired data leads to a sufficiently accurate subsurface image. For that purpose, methods for acquisition geometry analysis and design are available. These methods are used to judge whether an acquisition geometry is suited for the specified objectives. Conventional 2D and 3D...doctoral thesis 2015
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Staal, X.R. (author)Seismic imaging projects aim to reveal the structure of the earths crust from seismic data. These projects typically include three separate processing steps, being: attenuation of multiple reflections in the seismic data. estimating seismic wave propagation velocities from the seismic data. mapping the measured reflection data to the...doctoral thesis 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
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Ponziani, M. (author), Slob, E.C. (author), Luthi, S.M. (author), Bloemenkamp, R. (author), Le Nir, I. (author)We studied the electric response of fractures with laboratory experiments and numerical simulations for a full-bore formation microimaging tool. The laboratory setup was designed and built to perform controlled experiments with accurate measurements of all principal properties involved for electric borehole imaging. These properties are...journal article 2015
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Soni, A.K. (author), Verschuur, D.J. (author)For vertical-seismic-profiling (VSP) measurements, the use of blended acquisition, with time-overlapping shot records, can greatly reduce the downtime and, thereby, provide large cost savings. For directly imaging blended VSP measurements, we have used full-wavefield migration (FWM). FWM is an inversion-based imaging scheme that enables us to...journal article 2015
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Ozmen, N. (author), Dapp, R. (author), Zapf, M. (author), Gemmeke, H. (author), Ruiter, N.V. (author), Van Dongen, K.W.A. (author)Ultrasound is frequently used to evaluate suspicious masses in breasts. These evaluations could be improved by taking advantage of advanced imaging algorithms, which become feasible for low frequencies if accurate knowledge about the phase and amplitude of the wave field illuminating the volume of interest is available. In this study, we compare...journal article 2015
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Agbana, T.E. (author), Soloviev, O. (author), Bezzubik, V. (author), Patlan, V. (author), Verhaegen, M. (author), Vdovin, G.V. (author)We have implemented an extended depth of field optical system by wavefront coding with a micromachined membrane deformable mirror. This approach provides a versatile extension to standard wavefront coding based on fixed phase mask. First experimental results validate the feasibility of the use of adaptive optics for variable depth wavefront...conference paper 2015
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Minato, S. (author), Ghose, R. (author)Fluid flow through a fractured reservoir is often controlled by the large fractures. Seismically imaging these large fractures has the potential to illuminate their hydraulic properties.We derived a nonlinear imaging condition considering a medium containing nonwelded interfaces such as fractures for high-resolution fracture imaging. This was...journal article 2015
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Perenzoni, M. (author), Cavallo, D. (author)This paper describes and addresses the challenges that are encountered while designing a 900 GHz antenna for FET detectors using a standard submicron CMOS technology. The reduced metal stack, the problem of surface waves and technology-related rules are taken into account in order to properly design an efficient antenna, with the objective to...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 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
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On the focusing conditions in time-reversed acoustics, seismic interferometry, and Marchenko imagingWapenaar, 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
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Minato, S. (author), Ghose, R. (author)Hydraulic properties of a fractured reservoir are often controlled by large fractures. In order to seismically detect and characterize them, a high-resolution imaging method is necessary. We apply a non-linear imaging condition to image fractures, considered as non-welded interfaces. We derive the imaging condition from the general correlation...conference paper 2014
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Kumar, A. (author), Blacquiere, G. (author), Verschuur, D.J. (author)Recent advances in survey design have led to conventional common-midpoint-based analysis being replaced by the subsurface-based seismic acquisition analysis and design, with the emphasis on advance techniques of illumination analysis. Amongst them are wave-equation-based seismic illumination analyses such as the so-called focal beam method. The...conference paper 2014
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Vaissier, P.E.B. (author)Nowadays, tomographic imaging techniques are inseparable from modern medical practice as they allow non-invasive 3-dimensional visualization of the interior of a patient in order to e.g. establish a medical diagnosis, or to monitor disease progression and the effects of disease treatment. Next to clinical use, tomographic imaging techniques are...doctoral thesis 2014
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Frank, J.G. (author), Ruigrok, E.N. (author), Wapenaar, C.P.A. (author)Seismic interferometry allows for the creation of new seismic traces by cross correlating existing ones. With sufficient sampling of remote-source positions, it is possible to create a virtual source record by transforming a receiver location into a virtual source. The imaging technique developed here directly retrieves reflectivity information...journal article 2014
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Slob, E.C. (author), Wapenaar, C.P.A. (author), Broggini, F. (author), Snieder, R. (author)We present an imaging method that creates a map of reflection coefficients in correct one-way time with no contamination from internal multiples using purely a filtering approach. The filter is computed from the measured reflection response and does not require a background model. We demonstrate that the filter is a focusing wavefield that...journal article 2014
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Knibbe, H.P. (author), Mulder, W.A. (author), Oosterlee, C.W. (author), Vuik, C. (author)Three-dimensional reverse-time migration with the constant-density acoustic wave equation requires an efficient numerical scheme for the computation of wavefields. An explicit finite-difference scheme in the time domain is a common choice. However, it requires a significant amount of disk space for the imaging condition. The frequency-domain...journal article 2014