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Prior, M.K. (author), Ainslie, M.A. (author), Halvoresen, M. (author), Hartstra, I.E. (author), Laws, R. (author), MacGillvray, A. (author), Müller, R.A.J. (author), Wang, L. (author), Robinson, S. (author), van Heijningen, A.W.P. (author)
Measurements of sound emitted from airguns and airgun clusters are described. Measurements were made in 2007 and 2009-2010 in fjord environments in Norway and for various airgun types, chamber pressures, operating depths and airgun volumes. For each combination of these parameters, a sequence of up to 50 shots was performed, resulting in a few...
report 2021
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TNO Defensie en Veiligheid (author), Ainslie, M.A. (author), de Jong, C.A.F. (author), Dol, H.S. (author), Blacquière, G. (author), Marasini, C. (author)
For a proper (national) implementation of the European Union’s ambitious Marine Strategy Framework Directive, it is required that the impact of anthropogenic activities on the North Sea environment is assessed thoroughly. One of the effects of the use of the North Sea by humans is the generation of underwater sound. Sound propagates over longer...
report 2009
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van Vossen, R. (author), Ainslie, M.A. (author)
Predictions of sea-surface back-scattering strength are needed for sonar performance modelling. Such predictions are hampered by two problems. First, measurements of surface back-scattering are not available at small grazing angles. These are of special interest to low-frequency active sonar since they mainly contribute to long range propagation...
conference paper 2009
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van Vossen, R. (author), Colin, M. (author), Benders, F. (author), Ainslie, M.A. (author), Eidem, E.J. (author), Chalindar, B. (author), Juhel, B. (author), Dybedal, J. (author), Olsen, G.K. (author), Ivansson, S. (author), Abrahamsson, L. (author)
Accurate environmental information is required for obtaining reliable predictions for the performance of low-frequency active sonar (LFAS) systems. This environmental information is, however, often unreliable or unavailable. For example, the acoustic seabed parameters relevant for the scattering and reflection of sound at the seabed are commonly...
conference paper 2011
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Boek, W. (author), Ainslie, M.A. (author), TNO Defensie en Veiligheid (author)
A model is presented for simulating bistatic short-range reverberation in shallow water, in order to reproduce reverberation measurements made in the Vestfjorden area (Norway). During these measurements, a low frequency active sonar source was used to transmit short CW signals of frequency 1500 Hz and duration 10 ms. The echoes were received on...
conference paper 2006
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Ainslie, M.A. (author), Boek, W. (author), Nielsen, P.L. (author), Harrison, C.H. (author), TNO Defensie en Veiligheid (author)
A measurement of reverberation provides an opportunity to estimate geoacoustic parameters of the seabed by searching the relevant parameter space for a combination of inputs that, when fed into a reverberation model, best matches the measured data. The success of this process relies in part on the accuracy of the reverberation model used. In...
conference paper 2007
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Ainslie, M.A. (author), Leighton, T.G. (author)
A set of equations to describe the performance of sonar systems, collectively known as the “sonar equations”, was developed during and after the Second World War. These equations assumed that both the sonar equipment and the object to be detected (usually a submarine) would be submerged in one of Earth’s seas or oceans, and the efficacy of the...
conference paper 2015
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Zampolli, M. (author), Ainslie, M.A. (author), Schippers, P. (author), TNO Defensie en Veiligheid (author)
A set of eight sonar problems, pertaining to man-made active sonar, with source frequencies ranging from 250 Hz to 3.5 kHz, is defined. The scenarios are designed to emphasize range dependent propagation aspects in coastal waters, with the aim of testing all terms of the sonar equation (except the detection threshold) both before and after...
conference paper 2010
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Ainslie, M.A. (author), Dahl, P.H. (author), de Jong, C.A.F. (author), Laws, R.M. (author)
Geometrical spreading laws are widely used in underwater acoustics because they provide - if chosen carefully - an accuracy that is sufficient for many applications (source characterisation, impact assessment, sound mapping, regulation) for negligible computation time. The simplest and most widely used form is that corresponding to spherical...
conference paper 2014
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Dol, H.S. (author), Ainslie, M.A. (author), de Jong, C.A.F. (author), Blacquière, G. (author), van Riet, M. (author), TNO Defensie en Veiligheid TNO Industrie en Techniek (author)
This paper summarises the progress made by TNO on describing the most significant natural and anthropogenic sound sources in the North Sea (Dutch sector). An assessment of their relative importance is made by estimating an annual energy budget, not neglecting that details of the sound distribution in frequency, time and space might be equally...
conference paper 2009
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Sertlek, H.O. (author), Ainslie, M.A. (author)
Concern about possible impact of human activity on marine life has led to regulation in the USA [1,2] and the EU [3].The EU’s Marine Strategy Framework Directive [3] requires member states to achieve Good Environmental Status (GES) by 2020. Descriptor 11 of GES is “Introduction of energy, including underwater noise, is at levels that do not...
conference paper 2012
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Dekeling, R.P.A. (author), Tasker, M. (author), Ainslie, M.A. (author), Andersson, M. (author), André, M. (author), Borsani, F. (author), Brensing, K. (author), Castellote, M. (author), Dalen, J. (author), Folegot, T. (author), van der Graaf, S. (author), Leaper, R. (author), Liebschner, A. (author), Pajala, J. (author), Robinson, S. (author), Sigray, P. (author), Sutton, G. (author), Thomsen, F. (author), Werner, S. (author), Wittekind, D. (author)
The European Marine Strategy Framework Directive requires European member states to develop strategies for their marine waters that should lead to programmes of measures that achieve or maintain Good Environmental Status (GES) in all European seas by 2020. As an essential step towards reaching GES, member states should establish monitoring...
conference paper 2013
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von Benda-Beckmann, A.M. (author), van der Zwan, T. (author), van Riet, M.W.G. (author), Benders, F.P.A. (author), Ainslie, M.A. (author), te Raa, L.A. (author)
SAKAMATA is a risk assessment and mitigation tool developed by TNO and used by the Royal Netherlands Navy. It supports the user in planning and carrying out active sonar operations in an environmentally responsible way. Recently, a new version has been developed, which makes it possible to quantify the number of marine mammals affected, taking...
conference paper 2012
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Sertlek, H.O. (author), Ainslie, M.A. (author)
Accurate and fast estimation of propagation loss (PL) is needed for simulations of sonar or acoustic communication performance, and for environmental risk assessment. Accurate calculation of PL in range dependent and lossy waveguides can require computationally expensive wave theory techniques . In this work, a new propagation model is...
conference paper 2014
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Wittekind, D. (author), Tougaard, J. (author), Stilz, P. (author), Dähne, M. (author), Lucke, K. (author), Clark, C.W. (author), von Benda-Beckmann, A.M. (author), Ainslie, M.A. (author), Siebert, U. (author)
Functional marine mammal acoustic communication evolved under natural ambient noise levels, which makes communication vulnerable to intense, anthropogenic noise sources. We consider the potential long-range reduction effects of airgun noise on marine mammal communication range. During the propagation process, airgun impulses are reflected...
conference paper 2013
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Ainslie, M.A. (author), de Jong, C.A.F. (author)
Because of the history of sonar and sonar engineering, the concept of “source level” is widely used to characterize anthropogenic sound sources, but is it useful for sources other than sonar transmitters? The concept and applicability of source level are reviewed for sonar, air guns, explosions, ships, and pile drivers. International efforts...
conference paper 2016
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Dol, H.S. (author), Colin, M.E.G.D. (author), Ainslie, M.A. (author), van Walree, P.A. (author), Janmaat, J. (author)
Sea surface scattering by wind-generated waves and bubbles is regarded to be the main non-platform related cause of the time variability of shallow acoustic communication channels. Simulations for predicting the quality of acoustic communication links in such channels thus require adequate modeling of these dynamic sea-surface effects. It is...
conference paper 2012
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Cristol, X. (author), Jespers, S. (author), Chalindar, B. (author), Juhel, B. (author), Dybedal, J. (author), Eidem, E.J. (author), Ivansson, S. (author), van Vossen, R. (author), Ainslie, M.A. (author), Andersson, B.L. (author), Colin, M.E.G.D. (author), Pihl, J. (author)
The European Defence Agency project RUMBLE-2 (ref.[1]) offered the opportunity for investigating experimentally acoustic reverberation at about 1.kHz, under grazing incidence (less than about 20°), from very porous clayey seafloors of a continental shelf (mean grain size spanning from about 7 to 10 in  units); the instrument was an operational,...
conference paper 2012
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Abrahamsson, L. (author), Andersson, B.L. (author), Ivansson, S. (author), Pihl, J. (author), Chalindar, B. (author), Cristol, J.X. (author), Juhel, B. (author), Eidem, E.J. (author), Dybedal, J. (author), Olsen, G.K. (author), Ainslie, M.A. (author), Benders, F.P.A. (author), Colin, M.E.G.D. (author), van Vossen, R. (author)
An operational low-frequency active sonar system has been used in the EDA (European Defence Agency) project Rumble-2 to collect reverberation data at sea trials in the North Sea. Using a fast ray model for the forward computations, the reverberation data are inverted to determine bottom parameters: Lambert back-scattering parameter μ and sound...
conference paper 2012
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Juhel, B. (author), Cristol, X. (author), Chalindar, B. (author), Dybedal, J. (author), Eidem, E.J. (author), Ivansson, S. (author), van Vossen, R. (author), Ainslie, M.A. (author), Andersson, B.L. (author), Benders, F.P.A. (author), Colin, M.E.G.D. (author), Olsen, G.K. (author), Pihl, J. (author)
This paper presents the European Defence Agency project called “RUMBLE 2” carried out with contribution of several European organizations: TUS in France, TNO in the Netherlands, KDS and FFI in Norway, FOI in Sweden. The objective was to assess the capability of an operational Low Frequency Active Sonar (LFAS) to estimate bottom parameters in...
conference paper 2011
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