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Sahai, A.K. (author), Snellen, M. (author), Simons, D.G. (author)This paper presents an approach with which perceived audible differences in aircraft sounds can be quantified and presented in an objective manner. The objective quantification of the subjectively heard audible differences is intended to serve two primary goals. It can firstly enable developers of auralization technology to make the auralized...journal article 2018
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Manjunath, P. (author), Avallone, F. (author), Casalino, D. (author), Ragni, D. (author), Snellen, M. (author)Acoustic liners are widely used as noise suppression devices, for example in aircraft engines. The effectiveness of the liners is measured through the impedance. In the present study, using a lattice-Boltzmann solver, the response of two liner geometries to grazing acoustic waves is examined. The two geometries have porosity equal to 0.99%...conference paper 2018
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Merino Martinez, R. (author), Sanders, Martinus P.J. (author), Caldas, Luciano C. (author), Avallone, F. (author), Ragni, D. (author), de Santana, Leandro D. (author), Snellen, M. (author), Simons, D.G. (author)Microphone arrays are useful measurement devices for estimating the location and strength of sound sources. Numerous comparative studies have been conducted regarding the performance of acoustic imaging methods in the past, but literature lacks of a systematic investigation on the role of the hardware on the measurements. This research...conference paper 2018
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- Vieira, A.E. (author), Snellen, M. (author), Simons, D.G. (author) journal article 2018
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Mohammadloo, Tannaz H. (author), Snellen, M. (author), Simons, D.G. (author)In this contribution bathymetric uncertainties induced by the use of frequency modulated (FM) signals for multi-beam-echo-sounder (MBES) measurements are quantified and their relevance for MBES bathymetric uncertainty predictions is assessed. When switching to FM, the quality of depth measurements can get deteriorated due to the Doppler...journal article 2018
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Gaida, T.C. (author), Snellen, M. (author), van Dijk, Thaiënne A.G.P. (author), Simons, D.G. (author)Extensive seabed sediment mapping is highly relevant to describe marine ecosystems and to quantify the distribution and extent of benthic habitats. Compared to traditional mapping methods, primarily based on bed sampling, multibeam echo sounding (MBES) is a time-efficient tool to acquire high-resolution bathymetric and backscatter data over...journal article 2018
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Merino Martinez, R. (author), Heblij, Sander (author), Bergmans, Dick H.T. (author), Snellen, M. (author), Simons, D.G. (author)Accurate predictions of aircraft noise levels are desirable to enforce noise control regulations around airports and to evaluate noise abatement procedures. The current best practice noise contour prediction models assume certain default net thrust values depending on the engine type and aircraft altitude. This Paper proposes a method for...journal article 2018
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Merino Martinez, R. (author), Neri, Eleonora (author), Snellen, M. (author), Kennedy, John (author), Simons, D.G. (author), Bennett, Gareth J. (author)The noise emissions of a full-scale nose landing gear, measured in a wind tunnel and obtained from computational simulations, are compared with those of three regional aircraft types recorded in flyover measurements. The results from these three approaches are also compared with the predictions of two airframe noise models (Fink and Guo). The...conference paper 2018
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Arce Leon, C.A. (author), Merino Martinez, R. (author), Ragni, D. (author), Avallone, F. (author), Scarano, F. (author), Pröbsting, S. (author), Snellen, M. (author), Simons, D.G. (author), Madsen, Jesper (author)The broadband noise generated by the scattering of turbulent flow at the trailing edge of a NACA 0018 airfoil with trailing edge serrations is investigated, varying both the airfoil angle of attack and serration flap angle. Acoustic emissions from the trailing edge are measured using a microphone array. The noise level is observed to be...journal article 2017
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Snellen, I. A G (author), Désert, J. M. (author), Waters, L. B.F.M. (author), Robinson, T (author), Meadows, V. (author), van Dishoeck, E.F. (author), Brandl, B.R. (author), Henning, T. (author), Bouwman, J. (author), Lahuis, F. (author), Min, M. (author), Lovis, C. (author), Dominik, C. (author), Van Eylen, V. (author), Sing, D. (author), Anglada-Escudé, G. (author), Birkby, J. L. (author), Brogi, M. (author)Exoplanet Proxima b will be an important laboratory for the search for extraterrestrial life for the decades ahead. Here, we discuss the prospects of detecting carbon dioxide at 15 μm using a spectral filtering technique with the Medium Resolution Spectrograph (MRS) mode of the Mid-Infrared Instrument (MIRI) on the James Webb Space Telescope ...journal article 2017
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Sijtsma, P. (author), Merino Martinez, R. (author), Malgoezar, A.M.N. (author), Snellen, M. (author)In this article, a high-resolution extension of CLEAN-SC is proposed: high-resolution-CLEAN-SC. Where CLEAN-SC uses peak sources in ‘dirty maps’ to define so-called source components, high-resolution-CLEAN-SC takes advantage of the fact that source components can likewise be derived from points at some distance from the peak, as long as these...journal article 2017
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- Merino Martinez, R. (author), Neri, Eleonora (author), Snellen, M. (author), Kennedy, J (author), Simons, D.G. (author), Bennett, Gareth J. (author) conference paper 2017
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Mohammadloo, Tannaz H. (author), Tengku Ali, T.A. (author), Snellen, M. (author), Koop, L. (author), Gaida, T.C. (author), Simons, D.G. (author)Knowing the morphology and sediment composition of the seabed is of high importance for various applications. In this contribution, the repeatability of acoustic seafloor classification (ASC) results obtained from MBES backscatter value is investigated. The unsupervised classification algorithm based on Principal Component Analysis has been...conference paper 2017
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Mohammadloo, Tannaz H. (author), Snellen, M. (author), Simons, D.G. (author)The most recent generation multi-beam echosounders (MBES) allows to transmit Frequency Modulated (FM) signals, in addition to the more conventional Continuous Wave (CW) pulses. In this contribution, the effect of using these FM pulses for bathymetric measurements is investigated. Advantage of using FM signals is that measurements can be taken at...conference paper 2017
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- Mohammadloo, Tannaz H. (author), Snellen, M. (author), Simons, D.G. (author), Dierikx, Ben (author), Bicknese, Simon (author) conference paper 2017
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Sahai, A.K. (author), Yael Pereda Albarran, Miguel (author), Snellen, M. (author)This paper presents an analysis of how flying Continuous Descent Approaches (CDAs) can affect the quality of sounds that aircraft produce in airport vicinities. It is well known that CDAs present potential benefits in terms of community noise impact with reductions in excess of 5 dBA in peak noise levels. It is however unclear if these...poster 2017
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- Sarradj, Ennes (author), Herold, Gert (author), Sijtsma, P. (author), Merino Martinez, R. (author), Malgoezar, A.M.N. (author), Snellen, M. (author), Geyer, Thomas F. (author), Bahr, Christopher J. (author), Porteous, Ric (author), Moreau , Danielle J. (author), Doolan, Con J. (author) conference paper 2017
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Evers, L.G. (author), Wapenaar, C.P.A. (author), Heaney, KD (author), Snellen, M. (author)The propagation of acoustic waves in the ocean strongly depends on the temperature. Lowfrequency acoustic waves can penetrate the ocean down to depths where few in situ measurements are available. It is therefore attractive to obtain a measure of the deep ocean temperature from acoustic waves. The latter is especially true if the ambient...journal article 2017
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- Sahai, A.K. (author), Snellen, M. (author), Simons, D.G. (author), Stumpf, E (author) journal article 2017
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- Snellen, M. (author), Merino Martinez, R. (author), Simons, D.G. (author) journal article 2017