2019_programme: PROGRESS ON INTERNATIONAL STANDARDS FOR MEASUREMENT OF UNDERWATER NOISE FROM VESSELS

• Session: 02. Underwater acoustic calibration, testing, facilities and standards
  Organiser(s): Robinson Stephen, Humphrey Victor, Linné Markus, Évora Victor
• Lecture: PROGRESS ON INTERNATIONAL STANDARDS FOR MEASUREMENT OF UNDERWATER NOISE FROM VESSELS [invited]
  Paper ID: 965
  Author(s): Humphrey Victor, Cen Yin, Robinson Stephen, Wang Lian
  Presenter: Humphrey Victor
  Presentation type: oral
  Abstract: The environmental issues associated with underwater noise have led to a growing interest in the measurement of the noise radiated from surface vessels. ANSI and ISO have supported this by issuing standards for the measurement of the Radiated Noise Level (RNL) of vessels in deep water. Environmental noise models need a measure of the source level rather than the RNL and a standard indicating how to perform this conversion is at an advanced stage of preparation. However, many operators and investigators are constrained to making measurements in shallow water where both sea-surface and seabed effects are important. This issue is currently being addressed by a working group who have been performing a range of numerical calculations in order to study the principle issues involved; these have enabled the variability of the correction factor required to convert measurements of received pressure into the equivalent Monopole Source Level to be studied in such an environment. Examples of these calculations looking at the effects of the reflection at both the sea-surface and an attenuating seabed will be presented together with the influences of the water depth, seabed type, distance of closest approach, and number and location of the hydrophones. The results show how the correction factor varies and indicate the extent to which simplified approximations can be used for the correction factor.
• Corresponding author: Prof Humphrey Victor
  Affiliation: University of Southampton
  Country: United Kingdom
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