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document
Bosschaart, C. (author), Jansen, H.W. (author), de Jong, C.A.F. (author), Basten, T. (author)
A concept for underwater machinery noise mitigation of future civil and military ships is the application of a common deck structure, supporting multiple machines, which is installed on resilient mounts on the ship's foundation structure. TNO is addressing the availability and testing of tools to be able to set realistic targets for the radiated...
conference paper 2017
document
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
document
Thomsen, F. (author), Borsani, F. (author), Clarke, D. (author), de Jong, C. (author), de Wit, P. (author), Goethals, F. (author), Holtkamp, M. (author), Martin, E.S. (author), Spadaro, P. (author), van Raalte, G. (author), Victor, G.Y.V. (author), Jensen, A. (author)
The World Organization of Dredging Associations (WODA) has identified underwater sound as an environmental issue that needs further consideration. A WODA Expert Group on Underwater Sound (WEGUS) prepared a guidance paper in 2013 on dredging sound, including a summary of potential impacts on aquatic biota and advice on underwater sound monitoring...
conference paper 2016
document
de Jong, C.A.F. (author), Ainslie, M.A. (author), Heinis, F. (author), Janmaat, J. (author)
The underwater sound produced during construction of the Port of Rotterdam harbor extension (Maasvlakte 2) was measured, with emphasis on the contribution of the trailing suction hopper dredgers during their various activities: dredging, transport, and discharge of sediment. Measured source levels of the dredgers, estimated source levels of...
bookPart 2016
document
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
document
Zampolli, M. (author), Nijhof, M.J.J. (author), de Jong, C.A.F. (author), Ainslie, M.A. (author), Jansen, E.H.W. (author), Quesson, B.A.J. (author)
The acoustic radiation from a pile being driven into the sediment by a sequence of hammer strikes is studied with a linear, axisymmetric, structural acoustic frequency domain finite element model. Each hammer strike results in an impulsive sound that is emitted from the pile and then propagated in the shallow water waveguide. Measurements from...
article 2013
document
Ainslie, M.A. (author), Zampolli, M. (author), Ellis, D.D. (author)
The need for benchmarks of propagation loss, expressed eloquently by Felsen [1], was addressed in a series of propagation workshops in the 1980s. The main results of these workshops were a set of well defined propagation scenarios [2, 3] and a corresponding set of benchmark solutions [4, 5], which led in time to reliable models becoming...
conference paper 2012
document
Ainslie, M.A. (author), von Benda-Beckmann, A.M. (author)
To reduce the risk of impact on marine life of underwater sound generated by anthropogenic activities (such as offshore construction, seismic surveys and sonar searches), various mitigation measures are often put in place. Two commonly adopted mitigation measures are the soft start (or "ramp-up" – the two terms are used interchangeably) and ...
conference paper 2012
document
Fillinger, L. (author), Hunter, A.J. (author), Zampolli, M. (author), Clarijs, M.C. (author)
Divers constitute a potential threat to waterside infrastructures. Active diver detection sonars are available commercially but present some shortcomings, particularly in highly reverberant environments. This has led to research on passive sonar for diver detection. Passive detection of open-circuit UBA (underwater breathing apparatus) has been...
article 2012
document
Ainslie, M.A. (author), Dekeling, R.P.A. (author)
Cumulative acoustic exposure is used as an indicator for the risk of negative impact to animals as a consequence of exposure to underwater sound. The free-field energy of a single source, defined as the total acoustic energy that would exist in the source’s free field, is shown to be closely related to the total cumulative exposure added over a...
conference paper 2011
document
Ainslie, M.A. (author), Leighton, T.G. (author)
In [M. A. Ainslie & T. G. Leighton, Underwater Acoustic Measurements (Heraklion, Crete, 2007), pp 571-576], the authors described a discrepancy between the radiation damping coefficients in the models due to Weston and to Medwin describing the scattering cross-section of a single spherical bubble. The resolution of that discrepancy [M. A....
conference paper 2011
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