Coupled mode transport theory for sound transmission through an ocean with random sound speed perturbations: Coherence in deep water environments

2013 ◽  
Vol 134 (4) ◽  
pp. 3119-3133 ◽  
Author(s):  
John A. Colosi ◽  
Tarun K. Chandrayadula ◽  
Alexander G. Voronovich ◽  
Vladimir E. Ostashev
Keyword(s):  
Deep Water ◽  
Sound Speed ◽  
Transport Theory ◽  
Sound Transmission ◽  
Coupled Mode

Temporal Coherence for Sound Transmission Through Fluctuating Deep Water with Adiabatic Perturbed Modes

2019 ◽  
Vol 28 (01) ◽  
pp. 1950001
Author(s):  
Xiaotao Yu ◽  
Linhui Peng ◽  
Gaokun Yu
Keyword(s):  
Perturbation Theory ◽  
Internal Waves ◽  
Deep Water ◽  
Transport Theory ◽  
Coherence Function ◽  
Sound Transmission ◽  
Temporal Coherence ◽  
Coherence Time ◽  
Low Frequencies ◽  
Coupled Mode

Adiabatic approximation (AP) combined with perturbation theory gives a fast normal-mode solution of temporal coherence for sound field in a two-dimensional deep water with time-varying random internal waves. Internal waves induced mode changes are deduced using the first-order perturbation theory [C. T. Tindle, L. M. O’Driscoll and C. J. Higham, Coupled mode perturbation theory of range dependence, J. Acoust. Soc. Am. 108(1) (2000) 76–83]. And mode perturbations in amplitude are neglected by the adiabatic method with wavenumber perturbations in phase merely considered. The AP expression of temporal coherence function is theoretically identical to the adiabatic transport equation theory [J. A. Colosi, T. K. Chandrayadula, A. G. Voronovich and V. E. Ostashev, Coupled mode transport theory for sound transmission through an ocean with random sound speed perturbations: Coherence in deep water environments, J. Acoust. Soc. Am. 134(4) (2013) 3119–3133]. Numerical results of the adiabatic temporal coherence function for several low frequencies and ranges up to 1000[Formula: see text]km are calculated. Then the coherence time scales obtained from the calculations are examined by a one-way coupled theory considering forward scattering [A. G. Voronovich, V. E. Ostashev and J. A. Colosi, Temporal coherence of acoustic signals in a fluctuating ocean, J. Acoust. Soc. Am. 129(6) (2011) 3590–3597]. Comparisons demonstrate that the range and frequency dependence of coherence time for both methods are quite close. And this shows good agreement with the well-known inverse frequency and inverse square root range laws. In addition, the internal wave energy dependence of coherence time is also studied.

scholarly journals Cluster Analysis of Deep Water Sound Speed Profiles in Indian Ocean

2019 ◽  
Vol 310 ◽  
pp. 052048
Author(s):  
Hua Wang ◽  
Yunbo Li ◽  
Qinghong Li ◽  
Xiangjun Yu
Keyword(s):  
Cluster Analysis ◽  
Indian Ocean ◽  
Deep Water ◽  
Sound Speed

Some Deep‐Water Sound‐Transmission Paths South of Cyprus

1964 ◽  
Vol 36 (11) ◽  
pp. 2124-2130 ◽  
Author(s):  
Lincoln Baxter ◽  
Robert Brockhurst ◽  
Earl E. Hays
Keyword(s):  
Deep Water ◽  
Sound Transmission

Comparison of Sound Propagation Characteristic between Deep and Shallow Water

2014 ◽  
Vol 577 ◽  
pp. 1198-1201
Author(s):  
Zhang Liang ◽  
Chun Xia Meng ◽  
Hai Tao Xiao
Keyword(s):  
Shallow Water ◽  
Deep Water ◽  
Sound Speed ◽  
Sound Propagation ◽  
Spherical Wave ◽  
Sound Field ◽  
Propagation Loss ◽  
Speed Profile ◽  
Sound Speed Profile ◽  
Propagation Law

The physical characteristics are compared between shallow and deep water, in physics and acoustics, respectively. There is a specific sound speed profile in deep water, which is different from which in shallow water, resulting in different sound propagation law between them. In this paper, the sound field distributions are simulated under respective typical sound speed profile. The color figures of sound intensity are obtained, in which the horizontal ordinate is distance, and the vertical ordinate is depth. Then we can get some important characteristics of sound propagation. The results show that the seabed boundary is an important influence on sound propagation in shallow water, and sound propagation loss in deep water convergent zone is visibly less than which in spherical wave spreading. We can realize the remote probing using the acoustic phenomenon.

An Efficient Coupled-Mode Formulation for Acoustic Propagation in Inhomogeneous Waveguides

2016 ◽  
Vol 24 (01) ◽  
pp. 1550019
Author(s):  
Chunmei Yang ◽  
Wenyu Luo ◽  
Renhe Zhang ◽  
Liangang Lyu ◽  
Fangli Qiao
Keyword(s):  
Water Column ◽  
Sound Speed ◽  
Sound Propagation ◽  
Acoustic Propagation ◽  
Two Dimensional ◽  
Speed Profile ◽  
Benchmark Problem ◽  
Sound Speed Profile ◽  
Coupled Mode ◽  
Sloping Bottom

The direct-global-matrix coupled-mode model (DGMCM) for sound propagation in range-dependent waveguides was recently developed by Luo et al. [A numerically stable coupled-mode formulation for acoustic propagation in range-dependent waveguides, Sci. China G: Phys. Mech. Astron. 55 (2012) 572–588]. A brief review of the formulation and characteristics of this model is given. This paper extends this model to deal with realistic problems involving an inhomogeneous water column and a penetrable sloping bottom. To this end, the normal mode model KRAKEN is adopted to provide local modal solutions and their associated coupling matrices. As a result, the extended DGMCM model is capable of providing full two-way solutions to two-dimensional (2D) realistic problems with a depth- and range-dependent sound speed profile as well as a penetrable sloping bottom. To validate this model, it is first applied to a benchmark problem of sound propagation in a plane-parallel waveguide with a depth- and range-dependent sound speed profile, and then it is applied to a problem involving both an inhomogeneous water column and a sloping bottom. Comparisons with the analytical solution proposed by DeSanto and with the numerical model COUPLE are also provided, which show that the extended DGMCM model is accurate and efficient and hence can serve as a benchmark for realistic problems of sound propagation in an inhomogeneous waveguide.

Sign in / Sign up

Export Citation Format

Share Document