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Weemstra, C. (author), de Laat, J.I. (author), Verdel, A. (author), Smets, P. (author)Instrumental timing and phase errors are a notorious problem in seismic data acquisition and processing. These can be frequency independent, for example due to clock drift, but may also be frequency dependent, for example due to imperfectly known instrument responses. A technique is presented that allows both types of errors to be recovered in a...article 2021
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van IJsseldijk, J.E. (author), Ruigrok, E. (author), Verdel, A. (author), Weemstra, C. (author)Global phases, viz. seismic phases that travel through the Earth’s core, can be used to locally image the crust by means of seismic interferometry. This method is known as Global Phase Seismic Interferometry (GloPSI). Traditionally, GloPSI retrieves low-frequency information (up to 1 Hz). Recent studies, however, suggest that there is high...article 2019
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Verdel, A. (author), van Haeringen, D. (author), Vandeweijer, V. (author), Carpentier, S. (author), Meekes, S. (author)We demonstrate in this geothermal exploration case study performed in The Netherlands that ambient noise seismic interferometry (ANSI) can be an effective and efficient method for obtaining surface wave dispersion curves, leading to shallow shear-wave velocity-depth profiles that can improve imaging of deep structures. As the ANSI method...conference paper 2019
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Martins, J.E. (author), Weemstra, C. (author), Ruigrok, E. (author), Verdel, A. (author), Jousset, P. (author), Hersir, G.P. (author)Tomographic imaging based on ambient seismic noise measurements has shown to be a powerful tool, especially in areas like Iceland, where the microseism illumination is excellent. In this paper, we produce a 3D S-wave tomographic image over the western Reykjanes Peninsula high-enthalpy geothermal fields and evaluate the reliability of the...article 2019
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de Laat, J. (author), Weemstra, C. (author), Verdel, A. (author), Jousset, P. (author), Blanck, H. (author)Timing errors are a notorious problem in seismic data acquisition and processing. A technique is presented that allows such time shifts to be detected and corrected in a systematic fashion. The methodology relies on virtual-source responses retrieved through the application of seismic interferometry (SI). In application to recordings of ambient...conference paper 2018
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Ruiz-Armenteros, A.M. (author), Lazecky, M. (author), Ruiz-Constan, A. (author), Bakon, M. (author), Delgado, J. Manuel (author), Sousa, J.J. (author), Galindo-Zaldivar, J. (author), de Galdeano, C.S. (author), Caro-Cuenca, M. (author), Martos-Rosillo, S. (author), Jimenez-Gavilan, P. (author), Perissin, D. (author)In this paper we analyze the subsidence behavior of a coastal area in the province of Malaga (Costa del Sol), southern Spain, in the period 1992-2018 using C-band SAR interferometry. The area comprises several zones of interest where continuous deformation has happened during the analyzed period. Using SAR data from ESA's ERS-1/2, Envisat, and...conference paper 2018
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Almagro Vidal, C. (author), van der Neut, J. (author), Verdel, A.R. (author), Hartstra, I.E. (author), Wapenaar, K. (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...article 2018
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Lesundak, A. (author), Voigt, D. (author), Cip, O. (author), van den Berg, S. (author)Homodyne interferometry with a frequency comb as multi-wavelength source is a powerful method to measure long distances with high accuracy. The measurement principle requires that individual comb modes are spectrally resolved, making hundreds or thousands of accurately known wavelengths available for interferometry. For this reason the method...article 2017
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van den Dool, T.C. (author), Gielesen, W. (author), Kamphues, F. (author), Loix, N. (author), Kooijman, P.P. (author), de Vries, C. (author), van Weers, H. (author), Fleury, K. (author), Stockman, Y. (author), Velsink, G. (author), Benoit, J. (author), Poupinet, A. (author), Sève, F. (author), TNO Industrie en Techniek (author)TNO, in cooperation with Micromega-Dynamics, SRON, Dutch Space and CSL, has designed a compact breadboard cryogenic delay line (figure 1) for use in future space interferometry missions. The work is performed under ESA contract 17.747/03 in preparation for the DARWIN mission. The breadboard (BB) delay line is representative of a flight mechanism...conference paper 2017
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Koek, W.D. (author), van Zwet, E.J. (author), Sadeghian Marnani, H. (author)Traditionally, (dark field) imaging based, particle detection systems rely on identifying a particle based on its irradiance. It can be shown that for a very smooth wafer with 0.1 nm surface roughness (rms) this approach results in a particle detection limit larger than 20 nm. By carefully studying the physical mechanism behind this practical...conference paper 2016
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Mora, A. (author), Biermann, M. (author), Bombrun, A. (author), Boyadjian, J. (author), Chassat, F. (author), Corberand, P. (author), Davidson, M. (author), Doyle, D. (author), Escolar, D. (author), Gielesen, W.L.M. (author), Guilpain, T. (author), Hernandez, J. (author), Kirschner, V. (author), Klioner, S.A. (author), Koeck, C. (author), Laine, B. (author), Lindegren, L. (author), Serpell, E. (author), Tatry, P. (author), Thoral, P. (author)The Gaia all-sky astrometric survey is challenged by several issues affecting the spacecraft stability. Amongst them, we find the focus evolution, straylight and basic angle variations Contrary to pre-launch expectations, the image quality is continuously evolving, during commissioning and the nominal mission. Payload decontaminations and...conference paper 2016
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Witvoet, G. (author), Human, J.D. (author), Maniscalco, M.P. (author)An active tilt mirror mechanism, meant for correction of the constellation breathing of the evolved Laser Interferometer Space Antenna, has been designed and realized. Its open-loop performance has been characterized in both time and frequency domain. Based on this, a feedback controller has been designed and the resulting closed-loop...conference paper 2016
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Verdel, A. (author), Wedemeijer, H. (author), Paap, B. (author), Vandeweijer, V. (author), Weemstra, C. (author), Jousset, P. (author), Franke, S. (author), Blanck, H. (author), Águstsson, K. (author), Hersir, G.P. (author)We present results from the application of ambient noise seismic interferometry (ANSI) to data that were recorded continuously in 2014 and 2015 at Iceland’s peninsula Reykjanes. The objective of this study is the retrieval of reflected body waves (P-waves) that provide high-resolution velocity-versus-depth as well as subsurface structural...conference paper 2016
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Ruiz-Constán, A. (author), Ruiz-Armenteros, A.M. (author), Lamas-Fernández, F. (author), Martos-Rosillo, S. (author), Delgado, J.M. (author), Bekaert, D.P.S. (author), Sousa, J.J. (author), Gil, A.J. (author), Caro Cuenca, M. (author), Hanssen, R.F. (author), Galindo-Zaldívar, J. (author), Sanz de Galdeano, C. (author)This study uses the InSAR technique to analyse ground subsidence due to intensive exploitation of an aquifer for agricultural and urban purposes in the Montellano town (SW Spain). The detailed deformation maps clearly show that the spatial and temporal extent of subsidence is controlled by piezometric level fluctuations and the thickness of...article 2016
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Fuhrmann, T. (author), Caro Cuenca, M. (author), Knöpfler, A. (author), van Leijen, F.J. (author), Mayer, M. (author), Westerhaus, M. (author), Hanssen, R.F. (author), Heck, B. (author)The intra-plate deformation of the Upper Rhine Graben (URG) located in Central Europe is investigated using geodetic measurement techniques. We present a new approach to calculate a combined velocity field from InSAR, levelling and GNSS measurements. As the expected tectonic movements in the URG area are small (less than 1mma−1), the best...article 2015
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Boullenger, B. (author), Verdel, A. (author), Paap, B. (author), Thorbecke, J. (author), Draganov, D. (author)Seismic interferometry applied to ambient-noise measurements allows the retrieval of the seismic response between pairs of receivers. We studied ambient-noise seismic interferometry (ANSI) to retrieve time-lapse reflection responses from a reservoir during CO<inf>2</inf> geologic sequestration, using the case of the experimental site of Ketzin,...article 2014
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Caro Cuenca, M. (author), Dheenathayalan, P. (author), van Rossum, W.L. (author), Hoogeboom, P. (author)SAR interferometry (InSAR) requires coherent radar reflections to measure ground displacements. Howev-er, natural coherent reflectors are not always available due to changes in the scattering properties of the ground, e.g., growing vegetation. Furthermore, the opportunistic nature of InSAR measurements can limit its use for infrastructure...conference paper 2014
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Chakkalakkal Abdulla, S.M. (author), Cheng, L.K. (author), van den Bosch, B. (author), Dijkhuizen, N. (author), Nieuwland, R.A. (author), Gielesen, W.L.M. (author), Lucas, J. (author), Boussard-Plédel, C. (author), Conseil, C. (author), Bureau, B. (author), do Carmo, J.P. (author)The DARWIN mission aims to detect weak infra-red emission lines from distant orbiting earth-like planets using nulling interferometry. This requires filtering of wavefront errors using single mode waveguides operating at a wavelength range of 6.5-20 μm. This article describes the optical design of the fibers, the manufacturing protocol, the...conference paper 2014
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Mora, A. (author), Biermann, M. (author), Brown, A.G.A. (author), Busonero, D. (author), Carminati, L. (author), Carrasco, J.M. (author), Chassat, F. (author), Erdmann, M. (author), Gielesen, W.L.M. (author), Jordi, C. (author), Katz, D. (author), Kohley, R. (author), Lindegren, L. (author), Loeffler, W. (author), Marchal, O. (author), Panuzzo, P. (author), Seabroke, G. (author), Sahlmann, J. (author), Serpell, E. (author), Serraller, I. (author), van Leeuwen, F. (author), van Reeven, W. (author), van den Dool, T.C. (author), Vosteen, L.L.A. (author)The Gaia payload ensures maximum passive stability using a single material, SiC, for most of its elements. Dedicated metrology instruments are, however, required to carry out two functions: monitoring the basic angle and refocusing the telescope. Two interferometers fed by the same laser are used to measure the basic angle changes at the level...conference paper 2014
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Boullenger, B. (author), Verdel, A. (author), Thorbecke, J. (author), Draganov, D. (author)Since 2008, CO2 has been injected at the demonstration site for CO2 sequestration in Ketzin, Germany. Since 2009, a permanent array of seismic receivers installed by TNO at the injection site has recorded passive data continuously. It is the intention of TNO to use seismic interferometry (SI) by cross-correlation applied to the recorded ambient...conference paper 2013