Numerical technique for computing the wide‐angle acoustic field in an ocean with range‐dependent velocity profiles
作者:
L. E. Estes,
G. Fain,
期刊:
The Journal of the Acoustical Society of America
(AIP Available online 1977)
卷期:
Volume 62,
issue 1
页码: 38-43
ISSN:0001-4966
年代: 1977
DOI:10.1121/1.381502
出版商: Acoustical Society of America
数据来源: AIP
摘要:
A numerical technique for the propagation of sound in the ocean where velocity is a function of both range and depth has been developed. The technique is not restricted to the narrow‐angle (parabolic) approximation and it reduces to an exact solution for a homogeneous media. The given field is transformed into a sum of plane waves via an FFT. This transformed field is propagated without approximation through a homogeneous space represented by an average wave number for that space. Updating the average wave number provides for Snell’s law bending in range. The variations from the average velocity are accounted for by summing deviations from the nominal phase to develop a group of direction‐sensitive phase correction masks. A weighted group of plane waves centered about each direction are inverse transformed for multiplication by the phase mask with the results summed. The choice of overlapping weights in the transformed space provides an approximate continuous phase correction mask for all directions. The functional relationship of range‐step size to frequency, angular spectrum, and velocity profiles are developed. Several results for a 1500‐m channel are shown.
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