ANSI/ASA S12.64-2009/Part 1

This standard describes the measurement systems, procedures, and methodologies used for thebeam aspect measurement of underwater sound pressure levels from ships for a given operatingcondition. The resulting quantities are reported as nominal source level values in one-third octavebands. It does not require the use of a specific ocean location, but the requirements for an ocean testsite are provided. The underwater sound pressure level measurements are performed in the far-fieldand then corrected to a reference distance of 1 m. This standard is applicable to any and all surfacevessels either manned or unmanned. This standard is not applicable to submerged vessels or toaircraft. Measurement systems are described for measurement of underwater sound pressure levelsand also the distance or range between the underwater transducers and the subject vessel.Processing and reporting of the data are described, and informational guidance is provided. Thisstandard does not specify or provide guidance on underwater noise criteria.