Abstract
Near surface sources of ambient noise, such as shipping and wind, excite only steeply traveling sound waves. After a sufficient range, the steepest are stripped away by loss mechanisms, such as bottom interaction. Consequently, the vertical directivity of surface generated noise is expected to be peaked about two (up- and down-going) angles with very little contribution near the horizontal. This expectation is not always met in measurements. A possible explanation, for the noise at the horizontal, is the random scattering of the up- and down-going waves by volume inhomogeneities caused by internal waves. The purpose of this paper is to demonstrate the validity of this hypothesis. The coupled power theory of Dozier and Tappert [J. Acoust. Soc. Am. 63, 353–365 (1978)], in an updated form, is applied to the calculation of noise due to distant near surface sources. The vertical directivity of the resultant field is shown to demonstrate that internal wave scattering can produce noise at the horizontal. Rough surface scattering is expected to have a similar effect.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
