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Ainslie, M.A. (author), TNO Defensie en Veiligheid (author)
Multipath ocean reverberation originating from the seabed in shallow isovelocity water, with particular attention to its information content in the cylindrical spreading and mode stripping regions, is considered. The reverberation is evaluated using Weston's flux integral method, both analytically with various simplifying approximations and...
article 2007
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de Theije, P.A.M. (author), Ainslie, M.A. (author), van Moll, C.A.M. (author), TNO Defensie en Veiligheid (author)
This paper considers statistical detection theory for a system of two geographically distributed sensors. The performance of the two main fusion rules (OR and AND) is evaluated in the absence and presence of position errors in the observations, by means of receiver operating characteristics (ROC) curves. The analysis is restricted to three...
article 2009
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Ainslie, M.A. (author), Morfey, C.L. (author), TNO Defensie en Veiligheid (author)
article 2005
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van der Schaar, M. (author), Ainslie, M.A. (author), Robinson, S.P. (author), Prior, M.K. (author), André, M. (author)
The growing scientific and societal concerns about the effects of underwater sound on marine ecosystems have been recently recognised through the introduction of several international initiatives, like the International Quiet Ocean Experiment, aimed at measuring the environmental impact of ocean noise on large spatial and temporal scales. From a...
article 2014
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von Benda-Beckmann, A.M. (author), Wensveen, P.J. (author), Kvadsheim, P.H. (author), Lam, F.P.A. (author), Miller, P.J.O. (author), Tyack, P.L. (author), Ainslie, M.A. (author)
Ramp-up or soft-start procedures (i.e., gradual increase in the source level) are used to mitigate the effect of sonar sound on marine mammals, although no one to date has tested whether ramp-up procedures are effective at reducing the effect of sound on marine mammals. We investigated the effectiveness of ramp-up procedures in reducing the area...
article 2013
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Lippert, T. (author), Ainslie, M.A. (author), von Estorff, O. (author)
Sound produced by marine pile driving activities poses a possible risk to marine life. The assessment and mitigation of this risk requires a precise prediction of the expected levels. An analytical approach to estimate the radiated sound exposure levels is presented, based on the axial symmetry of the problem, resulting in damped cylindrical...
article 2018
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Prior, M.K. (author), Duncan, A.J. (author), Sertlek, H.Ö. (author), Ainslie, M.A. (author)
Comparisons are made of sound pressure and particle acceleration predicted by two methods in the vicinity of two arrays of marine-seismic airguns. Data describing the array properties and the environmental conditions are taken from test cases designed to facilitate intermodel comparison.The two propagation approaches, one based on method of...
article 2019
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Ainslie, M.A. (author), Laws, R.M. (author), Sertlek, H.O. (author)
Computer models can be used to predict the sound field near an airgun or airgun array. The accuracy of such predictions can be assessed either by a process of verification (comparison with alternative theoretical solution to the same computational problem) or by validation (comparison with measurement). A set of verification test problems is...
article 2019
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Ainslie, M.A. (author)
The detection performance of an active sonar depends on the intensity of the signal (target echo) relative to that of a background of reverberation plus noise. The echo is calculated for a standard test problem by convolving the time-domain impulse response at the target position with itself. The same approach is applied to a closely related...
article 2013
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Wensveen, P.J. (author), von Benda-Beckmann, A.M. (author), Ainslie, M.A. (author), Lam, F.P.A. (author), Kvadsheim, P.H. (author), Tyack, P.L. (author), Miller, P.J.O. (author)
The behaviour of a marine mammal near a noise source can modulate the sound exposure it receives.We demonstrate that two long-finned pilot whales both surfaced in synchrony with consecutive arrivals of multiple sonar pulses. We then assess the effect of surfacing and other behavioural response strategies on the received cumulative sound exposure...
article 2015
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Sertlek, H.O. (author), Ainslie, M.A. (author)
In shallow water propagation, the sound field depends on the proximity of the receiver to the sea surface, the seabed, the source depth, and the complementary source depth. While normal mode theory can predict this depth dependence, it can be computationally intensive. In this work, an analytical solution is derived in terms of the Faddeeva...
article 2014
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Mountain, J.A.R. (author), Ainslie, M.A. (author), Martin, P.L.R. (author), Hughes, M.R. (author), Seto, L.Y. (author), Laker, R.A. (author), Robins, A.J. (author), TNO Fysisch en Elektronisch Laboratorium (author)
The merits of monostatic and bistatic geometries in terms of the evasion probability for area and barrier searches were described. Detection probabilities were calculated by generating signal excess surfaces for a given sonar geometry. Acoustic modeling and operational analysis allowed to detect the impact of the problem on performance and...
article 2001
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Ainslie, M.A. (author), TNO Defensie en Veiligheid (author)
article 2010
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van Walree, P.A. (author), Ainslie, M.A. (author), Simons, D.G. (author), TNO Defensie en Veiligheid (author)
Echo energies of single-beam echo sounders are inverted for the sediment mean grain size via a combination of theoretical and empirical relationships. In situ measurements of the seafloor mass density have revealed the presence of a thin transition layer between the water and the sediment. Within this layer, which has a thickness of order 1 cm,...
article 2006
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Sivle, L.D. (author), Kvadsheim, P.H. (author), Ainslie, M.A. (author)
For conservation purposes, it is important to evaluate potential population consequences of noise disturbance. Based on maximum reported sound levels of no response to sonar, a mathematical model is used to predict the potential risk to the population of herring (Clupea harengus) when these levels are exceeded. Results show that risk varies with...
article 2015
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Ainslie, M.A. (author), Attenborough, K. (author), TNO Defensie en Veiligheid (author)
article 2009
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von Benda-Beckmann, A.M. (author), Thomas, L. (author), Tyack, P.L. (author), Ainslie, M.A. (author)
Passive acoustic monitoring with widely-dispersed hydrophones has been suggested as a cost-effective method to monitor population densities of echolocating marine mammals. This requires an estimate of the area around each receiver over which vocalizations are detected - the "effective detection area" (EDA). In the absence of auxiliary...
article 2018
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Ainslie, M.A. (author), Leighton, T.G. (author)
The set of formulations commonly known as “the sonar equations” have for many decades been used to quantify the performance of sonar systems in terms of their ability to detect and ocalize objects submerged in seawater. The efficacy of the sonar equations, with individualterms evaluated in decibels, is well established in Earth’s oceans. The...
article 2016
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Ainslie, M.A. (author), Halvorsen, M.B. (author), Müller, R.A.J. (author), Lippert, T. (author)
Environmental risk assessment for impact pile driving requires characterization of the radiated sound field. Damped cylindrical spreading (DCS) describes propagation of the acoustic Mach cone generated by striking a pile and predicts sound exposure level (LE) versus range. For known water depth and sediment properties, DCS permits extrapolation...
article 2020
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van Vossen, R. (author), Eidem, E.J. (author), Ivansson, S. (author), Chalindar, B. (author), Dybedal, J. (author), Colin, M.E.G.D. (author), Benders, F.P.A. (author), Andersson, B.L. (author), Juhel, B. (author), Cristol, X. (author), Olsen, G.K. (author), Pihl, J.N.B. (author), Tveit, E. (author), Jespers, S. (author), Ainslie, M.A. (author)
Accurate environmental information is required for obtaining confident sonar performance predictions. This environmental information is, however, often unreliable or unavailable. To support antisubmarine warfare (ASW) operations, a through-the-sensor approach has been developed in which relevant acoustic seabed properties are derived from...
article 2014
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