Understanding Radiated Underwater Noise Levels Measured at Different Sound Ranges
* Presenting author
Underwater noise "pollution" is an issue gaining importance in the public domain and moving towards international regulations for merchant shipping. Therefore, measuring radiated noise and determining the correct source levels in beam aspect becomes relevant. An important topic is the reported ship acoustic signature at different ranges with various hydrophone configurations and how the environment – deep water vs. shallow water - affects the measurements of radiated underwater noise.During the international trial RIMPASSE 2011, for both the research vessels CFAV Quest and RV Planet, acoustic trials were conducted at shallow and deep water sound ranges throughout Europe, using predefined conditions and procedures. The consistency of the platforms as noise sources was monitored by means of a large number of on-board mounted accelerometers.The contribution of the auxiliary machineries of both vessels was measured at the static sound ranges of Loch Goil (UK) and Aschau (GE). Sailing runs for the determination of the overall noise contribution were carried out at the dynamic sound ranges of Loch Fyne (UK), Heggernes (NO) and Aschau.Because of the limited time and space, this paper is mainly confined to the range comparison of beam aspect radiated underwater noise levels of the research vessel Planet.