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Abel, Felix (author), Sundaramoorthy, P.P. (author), Rajan, R.T. (author)Recently, an increase in distributed space systems and a rise in number of nodes in such systems is observed in numerous space applications, for example space-based interferometry. Such applications pose stringent demands on time synchronization which can be challenging to achieve for satellite networks that lack an absolute time reference...conference paper 2022
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Vilaboa Pérez, Jesús (author), Georges, Marc (author), Lenaerts, Cédric (author), Loicq, J.J.D. (author)We describe the state of development of a white light interferometer to characterize the cryogenic mirrors for GW detector on operation. We include the first experimental results from the proof of concept of the metrology instrument. The instrument will characterize the topology as well as the vibration of the mirrors. This development takes...conference paper 2022
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Caldarella, Nina (author), López-Dekker, Paco (author), Prats-Iraola, Pau (author), Nouguier, Frederic (author), Chapron, Bertrand (author), Zonno, Mariantonietta (author), Rodriguez-Cassola, Marc (author)Observations of wind and ocean surface velocity vectors by along-track interferometry (ATI) with the synthetic aperture radar (SAR) are not only important for direct applications but also to increase understandings of ocean upper layer mixing, air-ocean interactions, and mapping submesoscale (1-10 km) structures. An experimental bidirectional...journal article 2022
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Plumaris, M.K. (author), Dirkx, D. (author), Siemes, C. (author), Carraz, Olivier (author)Interplanetary missions have typically relied on Radio Science (RS) to recover gravity fields by detecting their signatures on the spacecraft trajectory. The weak gravitational fields of small bodies, coupled with the prominent influence of confounding accelerations, hinder the efficacy of this method. Meanwhile, quantum sensors based on Cold...journal article 2022
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Siemes, C. (author), Maddox, Stephen (author), Carraz, Olivier (author), Cross, Trevor (author), George, Steven (author), van den IJssel, J.A.A. (author), Kiss-Toth, Marton (author), Pastena, Massimiliano (author), Visser, P.N.A.M. (author)Cold Atom technology has undergone rapid development in recent years and has been demonstrated in space in the form of cold atom scientific experiments and technology demonstrators, but has so far not been used as the fundamental sensor technology in a science mission. The European Space Agency therefore funded a 7-month project to define the...journal article 2022
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van As, K. (author), Simons, Bram A. (author), Kleijn, C.R. (author), Kenjeres, S. (author), Bhattacharya, N. (author)We study how the speckle contrast depends on scatterer velocity, with the goal of further developing laser speckle imaging as a quantitative measurement technique. To that end, we perform interferometric computer simulations on a dilute plug flow. The results of our numerical experiment, that we compare with known analytical expressions to...journal article 2022
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Liu, J. (author), Draganov, D.S. (author), Ghose, R. (author)Seismic incoherent noise and waves scattered from objects in the crossline directions can cause 2D elastic full-waveform inversion (FWI) to produce artifacts in the resulting 2D models. We develop a complete workflow that can determine subsurface S-wave velocity (VS) models inverted from 2D near-surface seismic data more stably. We make use...journal article 2022
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Nazeer, N. (author), Groves, R.M. (author), Benedictus, R. (author)In this paper, with the final aim of shape sensing for a morphing aircraft wing section, a developed multimodal shape sensing system is analysed. We utilise the method of interrogating a morphing wing section based on the principles of both hybrid interferometry and Fibre Bragg Grating (FBG) spectral sensing described in our previous work....journal article 2022
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Inamdar, A.S. (author), Gromala, Przemyslaw Jakub (author), Prisacaru, Alexandru (author), Kabakchiev, Alexander (author), Yang, Yu Hsiang (author), Han, Bongtae (author)Epoxy molding compound (EMC) is widely used for encapsulating automotive electronics. Among all of the components of an electronic package, EMC is most exposed to the atmosphere, and thus undergoes aging. During high-temperature operation, EMC is oxidized, which alters its mechanical properties, and thus can affect the reliability of electronic...book chapter 2022
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Zhou, W. (author), Butcher, Antony (author), Brisbourne, Alex M. (author), Kufner, Sofia Katerina (author), Kendall, J. Michael (author), Stork, Anna L. (author)Firn densification profiles are an important parameter for ice-sheet mass balance and palaeoclimate studies. One conventional method of investigating firn profiles is using seismic refraction surveys, but these are difficult to upscale to large-area measurements. Distributed acoustic sensing (DAS) presents an opportunity for large-scale...journal article 2022
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Gurvits, L. (author), Falcke, Heino (author), Frey, Sándor (author), Fromm, Christian M. (author), García-Miró, Cristina (author), Janssen, Michael (author), Masania, K. (author), Rajan, R.T. (author), Visser, P.N.A.M. (author)Ultra-high angular resolution in astronomy has always been an important vehicle for making fundamental discoveries. Recent results in direct imaging of the vicinity of the supermassive black hole in the nucleus of the radio galaxy M87 by the millimeter VLBI system Event Horizon Telescope and various pioneering results of the Space VLBI...journal article 2022
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Conroy, Philip (author), van Diepen, S.A.N. (author), Van Asselen, Sanneke (author), Erkens, Gilles (author), van Leijen, F.J. (author), Hanssen, R.F. (author)Phase unwrapping, also known as ambiguity resolution, is an underdetermined problem in which assumptions must be made to obtain a result in SAR interferometry (InSAR) time series analysis. This problem is particularly acute for distributed scatterer InSAR, in which noise levels can be so large that they are comparable in magnitude to the...journal article 2022
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Plumaris, Michael (author)Interplanetary missions have relied on Radio Science (RS) for recovering gravity fields via detecting their signature on the spacecraft’s trajectory. Yet the weak gravitational fields of small bodies, coupled with the prominent influence of confounding accelerations, hinder the efficacy of this method. Meanwhile, quantum sensors based on Cold...master thesis 2021
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Siskins, M. (author)This thesis studies higher-order material properties* and effects in van der Waals crystals, such as anisotropic Young’s modulus, magnetostriction, and non-trivial thermal expansion effects near magnetic and electronic phase transitions, that can affect the nanomechanical motion ofmultilayer two-dimensional (2D) material membranes. These...doctoral thesis 2021
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van de Sande, Willem (author)A wavelength modulated interferometer is presented, based on a telecom laser source. A solution for the target distance dependency of wavelength modulated interferometers is presented. With the introduction of a delay line, the modulation depth variation is reduced. A method and a sensor head for the reduction of the thermal dependency of this...master thesis 2021
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Abel, Felix (author)In this thesis, we propose a new class of pairwise frequency, multi-domain time synchronization and ranging algorithms for anchorless mobile networks of asynchronous nodes. We apply these techniques and study network and mission level aspects of time synchronization to Orbiting Low Frequency Array for Radio astronomy (OLFAR), a proposed...master thesis 2021
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Ouali, Mouad (author)The Dutch infrastructure counts many bridges, the majority of which are built in concrete. These bridges have been designed and constructed according to safety codes. A lot of these bridges date from the previous century and have been designed conform outdated safety codes. Therefore, the main problem<br/>of these bridges is the uncertainty with...master thesis 2021
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Monitoring changes in the Groningen subsurface using non-physical arrivals in seismic interferometryShirmohammadi, F. (author), Draganov, D.S. (author), Wapenaar, C.P.A. (author)Seismic interferometry (SI) refers to the principle of generating seismic responses by crosscorrelating seismic observations at different receiver locations. Theory requires that the boundary sources emit the same energy, have regular spacing and are spaced densely enough. When these assumptions are not met, not only the desired physical...poster 2021
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Chamarczuk, M. (author), Malinowski, M. (author), Draganov, D.S. (author), Grant, A. (author), Asgharzadeh, M. (author), Urosevic, M. (author)Here we analyse ambient noise (AN) data generated during drilling of exploration boreholes and recorded using a dense array deployed over one of the numerous shallow iron-ore mineralization targets in the Pilbara region (Western Australia). Drilling and drilling-related operations were reoccurring in a sequence as described by the drillers’...journal article 2021
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Wapenaar, C.P.A. (author), Snieder, Roel (author), de Ridder, Sjoerd (author), Slob, E.C. (author)Marchenko methods are based on integral representations which express Green’s functions for virtual sources and/or receivers in the subsurface in terms of the reflection response at the surface. An underlying assumption is that inside the medium the wave field can be decomposed into downgoing and upgoing waves and that evanescent waves can be...journal article 2021