Formation, propagation, and focusing of acoustic beams in oceanic waveguides. The quasi-optics approximation

• Published in: Acoustical physics Vol. 54; no. 5; pp. 689 - 697
• Main Authors: Petukhov, Yu. V., Khil’ko, A. A.
• Format: Journal Article
• Language: English
• Published: Dordrecht SP MAIK Nauka/Interperiodica 01-09-2008
• Subjects: Acoustics; Ocean Acoustics and Underwater Sound; Physics; Physics and Astronomy; 43.30.+m
• ISSN: 1063-7710; 1562-6865
• DOI: 10.1134/S1063771008050138

Using the WKB approximation and assuming that the spatial spectrum of modes excited by a vertical array is sufficiently narrow, a quasi-optical theory is developed to describe the fundamental regularities manifesting themselves in the formation, propagation, and focusing of multimode acoustic beams in oceanic waveguides. Functional dependences on the parameters of both the transmitting array and the oceanic waveguide are obtained for horizontal distances at which ordinary beams form refraction focusing zones. Conditions ensuring the formation of a beam with the minimum wave front divergence are formulated for the distribution of the source excitation factor over the array aperture.