Searched for: subject%3A%22AS%255C%2B%255C-%255C%2BAcoustics%255C%2B%2526%255C%2BSonar%22
(321 - 340 of 342)
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Abrahamsson, L. (author), Andersson, B.L. (author), Ivansson, S. (author), Pihl, J. (author), Ainslie, M.A. (author), Benders, F.P.A. (author), Chalindar, B. (author), Colin, M.E.G.D. (author), Cristol, X. (author), Dybedal, J. (author), Eidem, E.J. (author), Juhel, B. (author), Olsen, G.K. (author), van Vossen, R. (author)Reverberation is a problem for active sonar operating in shallow waters, reducing detection probabilities and introducing false alarms. Within the European Defence Agency project Rumble-2, a demonstrator system has been developed for ”through the sensor” measurement of the bottom parameters needed to predict active sonar detection performance....conference paper 2011
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Nederlandse Organisatie voor Toegepast-Natuurwetenschappelijk Onderzoek (author), Colin, M.E.G.D. (author)The end of the Cold War and the collapse of the Warsaw pact have resulted in a change of operational theatre for the naval forces of the North Atlantic Treaty Organisation (NATO). In particular, the focus of Anti Submarine Warfare forces has shifted from tracking Soviet nuclear ballistic missile submarine in the deep waters of the Atlantic ocean...doctoral thesis 2011
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Colin, M.E.G.D. (author), von Benda-Beckmann, A.M. (author)Assets at sea are vulnerable to attacks from fast craft relying on the effect of surprise. These threats are not necessarily stealthy but leave a very limited time of reaction to the platform at risk. Early detection of the approaching vessel provides an opportunity for the attacked ship to react in time. Accurate localisation of the threat...conference paper 2011
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Clairbois, J.-P. (author), de Roo, F. (author), Garai, M. (author), Conter, M. (author), Defrance, J. (author), Oltean-Dumbrava, C. (author), Fusco, I. (author)Since the early 80's, one models noise propagation, in the early 90's one started to standardize how to measure the intrinsic characteristics of manufactured noise barriers: in 1997, the EU funded ADRIENNE research ([1] and [2]) was a first step, but many problems still remained. Since years, all the noise propagation software are still modeling...conference paper 2010
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Xu, B. (author), Wind, J. (author), de Bree, H.E. (author), Basten, T.G.H. (author), Druyvesteyn, E. (author), TNO Industrie en Techniek (author)An acoustic vector sensor array consists of multiple sound pressure microphones and particle velocity sensors. A pressure microphone usually has an omni-directional response, yet a particle velocity sensor is directional. Currently, acoustic vector sensor arrays are under investigation for far field source localization and visualization. One of...conference paper 2010
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Janssen, S.A. (author), Vos, H. (author), Eisses, A.R. (author), Pedersen, E. (author), TNO Bouw en Ondergrond TNO Industrie en Techniek (author)While wind turbines have beneficial effects for the environment, they inevitably generate environmental noise. In order to protect residents against unacceptable levels of noise, exposure-response relationships are needed to predict the expected percentage of people annoyed or highly annoyed at a given level of wind turbine noise. Exposure...conference paper 2010
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te Raa, L.A. (author), Verhave, J.A. (author), Driessen, F.P.G. (author), Dreschler, J. (author), TNO Defensie en Veiligheid (author)To improve port security capability there is a need for systems for detection, warning and deterrence of unwanted divers in harbour environments. In a complex environment such as a harbour, these topics present challenging problems and as such are subject to research and development. Already a few dedicated systems are commercially available,...conference paper 2010
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Bosschaart, C. (author), Eisses, A.R. (author), van der Eerden, F.J.M. (author)Amsterdam Airport Schiphol has organized a competition to design a noise mitigating measure along the 'Polderbaan' runway. Its main goal is to reduce the low frequency (LF) ground noise from starting aircraft. The winning concept is a flexible parabolic shaped noise barrier positioned relatively close to the runway. There is a large distance...conference paper 2010
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Basten, T.G.H. (author), Wind, J. (author), Xu, B. (author), de Bree, H.E. (author), Druyvesteyn, E. (author), TNO Industrie en Techniek (author)An acoustic vector sensor array consists of multiple sound pressure microphones and particle velocity sensors. A pressure microphone usually has an omni-directional response, yet a particle velocity sensor is directional and usually has a response pattern as a figure of eight. Currently, acoustic vector sensor arrays are under investigation for...conference paper 2010
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Berkhoff, A.P. (author)Applications are given of a preconditioned adaptive algorithm for broadband multichannel active noise control. Based on state-space descriptions of the relevant transfer functions, the algorithm uses the inverse of the minimum-phase part of the secondary path in order to improve the speed of convergence. A further improvement of the convergence...conference paper 2010
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Ainslie, M.A. (author), de Jong, C.A.F. (author), Robinson, S.P. (author), Lepper, P.A. (author)To meet the growing demand for carbon-free energy sources, the EU has ambitious plans to increase its capacity for generation of offshore wind power. The UK and Netherlands, for example, plan to increase their offshore power generating capacity, respectively, to 33 and 6 gigawatts by the year 2020. Assuming that this power is generated entirely...conference paper 2010
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Basten, T. (author), Berkhoff, A. (author), Vermeulen, R. (author), TNO Industrie en Techniek (author)Dutch navy ships are designed and built to have a low underwater signature. For low frequencies however, tonal vibrations of a gearbox can occur, which might lead to increased acoustic signatures. These vibrations are hard to reduce by passive means. To investigate the possibilities of active vibration control to reduce the underwater signature,...conference paper 2010
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Driessen, F.P.G. (author), te Raa, L.A. (author), Dreschler, J. (author), TNO Defensie en Veiligheid (author)To improve port security capability there is a need for systems for detection, warning and deterrence of unwanted divers in harbour environments. In a complex environment such as a harbour, these topics present challenging problems and as such are subject to research and development. Already a few dedicated systems are commercially available on...conference paper 2010
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Basten, T.G.H. (author), de Bree, H.-E. (author)Calibration of acoustic particle velocity sensors is still difficult due to the lack of standardized sensors to compare with. Recently it is shown by Jacobsen and Jaud [J. Acoust. Soc. Am. 120, 830-837 (2006)] that it is possible to calibrate a sound pressure and particle velocity sensor in free field conditions at higher frequencies. This is...article 2010
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Wessels, P.W. (author), Basten, T.G.H. (author), van der Eerden, F.J.M. (author)In this paper the approach for an acoustical model based monitoring network is demonstrated. This network is capable of reconstructing a noise map, based on the combination of measured sound levels and an acoustic model of the area. By pre-calculating the sound attenuation within the network the noise map can be shown in real-time. The...conference paper 2010
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Espana, A.L. (author), Williams, K.L. (author), Kargl, S.G. (author), Zampolli, M. (author), Marston, P.L. (author), TNO Defensie en Veiligheid (author)Recent experiments conducted in a fresh water pond investigated the monostatic scattering from an aluminum pipe (length-to-diameter ratio of 2) in the free field, as well as in a proud configuration on a flattened sand sediment. Synthetic aperture sonar (SAS) techniques are used to process the data. Absolute target strength is calculated over...conference paper 2010
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Ainslie, M.A. (author), TNO Defensie en Veiligheid (author)Sonar performance modelling (SPM) is concerned with the prediction of quantitative measures of sonar performance, such as probability of detection. It is a multidisciplinary subject, requiring knowledge and expertise in the disparate fields of underwater acoustics, acoustical oceanography, sonar signal processing and statistical detection theory...book 2010
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Fillinger, L. (author), de Theije, P.A.M. (author), Zampolli, M. (author), Sutin, A. (author), Salloum, H. (author), Sedunov, N. (author), Sedunov, A. (author), TNO Defensie en Veiligheid (author)The international rules for the protection of harbors against threats and intruders typically apply to threats emanating from the land side. Protection against actions and threats from the water side is much less regulated, apart from some individual cases. Potential threats from the water side may consist of intruders including divers with and...conference paper 2010
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Berkhoff, A.P. (author)This paper presents results obtained from a number of applications in which a recent adaptive algorithm for broadband multichannel active noise control is used. The core of the algorithm uses the inverse of the minimum-phase part of the secondary path for improvement of the speed of convergence. A further improvement of the speed of convergence...conference paper 2010
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van der Eerden, F.J.M. (author), van der Berg, F. (author)In the densely populated area of the Netherlands, the objective of the Netherlands Ministry of Defence is to find an optimal balance between military training and the impact on the surrounding civilian community. A special case concerns large weapons, such as artillery or demolitions, which create high-energy blast waves. These waves have a low...conference paper 2010
Searched for: subject%3A%22AS%255C%2B%255C-%255C%2BAcoustics%255C%2B%2526%255C%2BSonar%22
(321 - 340 of 342)