Fine structure of the sound‐speed profile in ocean bottom sediments from in situ measurements

1975 ◽  
Vol 57 (S1) ◽  
pp. S30-S30
Author(s):  
D. J. Shirley
Keyword(s):  
Fine Structure ◽  
Bottom Sediments ◽  
Sound Speed ◽  
In Situ Measurements ◽  
Ocean Bottom ◽  
Speed Profile ◽  
Sound Speed Profile

Compensation of INS Errors based on LBL References in a Quadratic Sound-Speed-Profile

2020 ◽  
Author(s):  
Yohannes S.M. Simamora ◽  
Harijono A. Tjokronegoro ◽  
Edi Leksono ◽  
Irsan S. Brodjonegoro
Keyword(s):  
Sound Speed ◽  
Speed Profile ◽  
Sound Speed Profile

Sound speed profile inversion using a horizontal line array in shallow water

2014 ◽  
Vol 58 (1) ◽  
pp. 1-7 ◽  
Author(s):  
ZhengLin Li ◽  
Li He ◽  
RenHe Zhang ◽  
FengHua Li ◽  
YanXin Yu ◽  
...  
Keyword(s):  
Shallow Water ◽  
Sound Speed ◽  
Horizontal Line ◽  
Speed Profile ◽  
Sound Speed Profile ◽  
Line Array ◽  
Profile Inversion

A Computationally Efficient Rayleigh–Ritz Model for Heterogeneous Oceanic Waveguides Using Fourier Series of Sound Speed Profile

2021 ◽  
pp. 2150015
Author(s):  
A. D. Chowdhury ◽  
S. K. Bhattacharyya ◽  
C. P. Vendhan
Keyword(s):  
Fourier Series ◽  
Sound Speed ◽  
Transmission Loss ◽  
Ritz Method ◽  
Computational Cost ◽  
Least Square ◽  
Speed Profile ◽  
Matrix Elements ◽  
Sound Speed Profile ◽  
The Matrix

The normal mode method is widely used in ocean acoustic propagation. Usually, finite difference and finite element methods are used in its solution. Recently, a method has been proposed for heterogeneous layered waveguides where the depth eigenproblem is solved using the classical Rayleigh–Ritz approximation. The method has high accuracy for low to high frequency problems. However, the matrices that appear in the eigenvalue problem for radial wavenumbers require numerical integration of the matrix elements since the sound speed and density profiles are numerically defined. In this paper, a technique is proposed to reduce the computational cost of the Rayleigh–Ritz method by expanding the sound speed profile in a Fourier series using nonlinear least square fit so that the integrals of the matrix elements can be computed in closed form. This technique is tested in a variety of problems and found to be sufficiently accurate in obtaining the radial wavenumbers as well as the transmission loss in a waveguide. The computational savings obtained by this approach is remarkable, the improvements being one or two orders of magnitude.

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