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Meskers, A.J.H. (author), Spronck, J.W. (author), Munnig Schmidt, R.H. (author)The use of optical fibers presents several advantages with respect to free-space optical transport regarding sourcefrequency delivery to individual heterodyne interferometers. Unfortunately, fiber delivery to individual coaxial heterodyne interferometers leads to an increase of (periodic) nonlinearity in the measurement, because transporting...journal article 2014
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Joo, K.N. (author), Ellis, J.D. (author), Spronck, J.W. (author), Van Kan, P.J.M. (author), Munnig Schmidt, R.H. (author)We describe a simple heterodyne laser interferometer that has subnanometer periodic errors and is applicable to industrial fields. Two spatially separated beams can reduce the periodic errors, and the use of a right-angle prism makes the optical configuration much simpler than previous interferometers. Moreover, the optical resolution can be...journal article 2009
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Van der Neut, J. (author), Herrmann, F.J. (author)Assuming that transmission responses are known between the surface and a particular depth level in the subsurface, seismic sources can be effectively mapped to this level by a process called interferometric redatuming. After redatuming, the obtained wavefields can be used for imaging below this particular depth level. Interferometric redatuming...journal article 2012
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Spronck, J. (author), Pereira, S.F. (author), Braat, J.J.M. (author)We introduce a new concept of nulling interferometer without any achromatic device, using polarization properties of light. This type of interferometer should enable a high rejection ratio in a theoretically unlimited spectral band. We analyze several consequences of the proposed design, notably, the possibility of fast internal modulation.journal article 2006
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Mahajan, V.N. (author), Aftab, M. (author)The theory of wavefront analysis of a noncircular wavefront is given and applied for a systematic comparison of the use of annular and Zernike circle polynomials for the analysis of an annular wavefront. It is shown that, unlike the annular coefficients, the circle coefficients generally change as the number of polynomials used in the expansion...journal article 2010
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Draganov, D.S. (author), Ghose, R. (author), Heller, K. (author), Ruigrok, E.N. (author)Application of seismic interferometry to records from receivers at the Earth’s surface from sources in wells retrieves the reflection response measured at the receivers as if from virtual sources located also at the surface. When the wavefields experience intrinsic losses during propagation, non-physical arrivals (ghosts) would appear in the...journal article 2012
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Montilla, I. (author), Pereira, S.F. (author), Braat, J.J.M. (author)A new interferometric technique for Michelson wide-field interferometry is presented that consists of a Michelson pupil-plane combination scheme in which a wide field of view can be achieved in one shot. This technique uses a stair-shaped mirror in the intermediate image plane of each telescope in the array, allowing for simultaneous correction...journal article 2005
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Wapenaar, C.P.A. (author), Draganov, D.S. (author), Snieder, R. (author), Campman, X. (author), Verdel, A. (author)Seismic interferometry involves the crosscorrelation of responses at different receivers to obtain the Green's function between these receivers. For the simple situation of an impulsive plane wave propagating along the x-axis, the crosscorrelation of the responses at two receivers along the x-axis gives the Green's function of the direct wave...journal article 2010
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Spronck, J. (author), Pereira, S.F. (author), Braat, J.J.M. (author)We introduce the concept of chromatism compensation in nulling interferometry that enables a high rejection ratio in a wide spectral band. Therefore the achromaticity condition considered in most nulling interferometers can be relaxed. We show that this chromatism compensation cannot be applied to a two-beam nulling interferometer, and we make...journal article 2006
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Wapenaar, C.P.A. (author), Slob, E.C. (author)Recent work on the Marchenko equation has shown that the scalar 3-D Green’s function for a virtual source in the subsurface can be retrieved from the single-sided reflection response at the surface and an estimate of the direct arrival. Here, we discuss the first steps towards extending this result to multicomponent data. After introducing a...journal article 2014
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Wapenaar, C.P.A. (author), Slob, E.C. (author), Snieder, R. (author), Curtis, A. (author)In the 1990s, the method of time-reversed acoustics was developed. This method exploits the fact that the acoustic wave equation for a lossless medium is invariant for time reversal. When ultrasonic responses recorded by piezoelectric transducers are reversed in time and fed simultaneously as source signals to the transducers, they focus at the...journal article 2010
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Draganov, D.S. (author), Wapenaar, K. (author), Mulder, W. (author), Singer, J. (author), Verdel, A. (author)The retrieval of the earth's reflection response from cross?correlations of seismic noise recordings can provide valuable information, which may otherwise not be available due to limited spatial distribution of seismic sources. We cross?correlated ten hours of seismic background?noise data acquired in a desert area. The cross?correlation results...journal article 2007
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Rajan, R.T. (author), Boonstra, A.J. (author), Bentum, M. (author), Klein-Wolt, M. (author), Belien, F. (author), Arts, M. (author), Saks, N. (author), Van der Veen, A.J. (author)The past decade has seen the advent of various radio astronomy arrays, particularly for low-frequency observations below 100 MHz. These developments have been primarily driven by interesting and fundamental scientific questions, such as studying the dark ages and epoch of re-ionization, by detecting the highly red-shifted 21 cm line emission....journal article 2015
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Ellis, J.D. (author), Meskers, A.J.H. (author), Spronck, J.W. (author), Munnig Schmidt, R.H. (author)Displacement interferometry is widely used for accurately characterizing nanometer and subnanometer displacements in many applications. In many modern systems, fiber delivery is desired to limit optical alignment and remove heat sources from the system, but fiber delivery can exacerbate common interferometric measurement problems, such as...journal article 2011
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Swinkels, B.L. (author), Bhattacharya, N. (author), Braat, J.J.M. (author)Absolute distance measurements can be performed with an interferometric method that uses only a single tunable laser. This method has one major drawback, because a small target movement of the order of one wavelength during a measurement will be interpreted as a movement of one synthetic wavelength. This effect is usually mitigated by adding a...journal article 2005
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Curtis, A. (author), Gerstoft, P. (author), Sato, H. (author), Snieder, R. (author), Wapenaar, C.P.A. (author)Turning noise into useful data—every geophysicist's dream? And now it seems possible. The field of seismic interferometry has at its foundation a shift in the way we think about the parts of the signal that are currently filtered out of most analyses—complicated seismic codas (the multiply scattered parts of seismic waveforms) and background...journal article 2006
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Ruigrok, E.N. (author), Campman, X. (author), Draganov, D.S. (author), Wapenaar, K. (author)In recent years, there has been an increase in the deployment of relatively dense arrays of seismic stations. The availability of spatially densely sampled global and regional seismic data has stimulated the adoption of industry-style imaging algorithms applied to converted- and scattered-wave energy from distant earthquakes, leading to...journal article 2010
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Draganov, D.S. (author), Wapenaar, C.P.A. (author), Thorbecke, J.W. (author)In 1968, Jon Claerbout showed that the reflection response of a 1D acoustic medium can be reconstructed by autocorrelating the transmission response. Since then, several authors have derived relationships for reconstructing Green's functions at the surface, using crosscorrelations of (noise) recordings that were taken at the surface and that...journal article 2006
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Minato, S. (author), Matsuoka, T. (author), Tsuji, T. (author), Draganov, D.S. (author), Hunziker, J.W. (author), Wapenaar, C.P.A. (author)Crosswell reflection method is a high-resolution seismic imaging method that uses recordings between boreholes. The need for downhole sources is a restrictive factor in its application, for example, to time-lapse surveys. An alternative is to use surface sources in combination with seismic interferometry. Seismic interferometry (SI) could...journal article 2011
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Van Dalen, K.N. (author), Wapenaar, C.P.A. (author), Halliday, D.F. (author)Virtual-source surface wave responses can be retrieved using the crosscorrelation (CC) of wavefields observed at two receivers. Higher mode surface waves cannot be properly retrieved when there is a lack of subsurface sources that excite these wavefields, as is often the case. In this paper, we present a multidimensional-deconvolution (MDD)...journal article 2013