Studies on water column nutrient distribution and sound speed profile variations along coastal region of India

2018 ◽  
Vol 144 (3) ◽  
pp. 1948-1948
Author(s):  
Sakthivel M. Santhanam
Keyword(s):  
Water Column ◽  
Sound Speed ◽  
Coastal Region ◽  
Speed Profile ◽  
Nutrient Distribution ◽  
Sound Speed Profile ◽  
Water Column Nutrient

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.

scholarly journals Automatic Identification of Internal Wave Characteristics Affecting Bathymetric Measurement Based on Multibeam Echosounder Water Column Data Analysis

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4774
Author(s):  
Karolina Zwolak ◽  
Łukasz Marchel ◽  
Aileen Bohan ◽  
Masanao Sumiyoshi ◽  
Jaya Roperez ◽  
...  
Keyword(s):  
Water Column ◽  
Sound Speed ◽  
Water Mass ◽  
Automatic Identification ◽  
Speed Profile ◽  
Sound Speed Profile ◽  
Multibeam Echosounder ◽  
Data Collection And Analysis ◽  
Mass Stratification ◽  
Ray Bending

The accuracy of multibeam echosounder bathymetric measurement depends on the accuracy of the data of the sound speed layers within the water column. This is necessary for the correct modeling of ray bending. It is assumed that the sound speed layers are horizontal and static, according to the sound speed profile traditionally used in the depth calculation. In fact, the boundaries between varying water masses can be curved and oscillate. It is difficult to assess the parameters of these movements based on the sparse sampling of sound velocity profiles (SVP) collected through a survey; thus, alternative or augmented methods are needed to obtain information about water mass stratification for the time of a particular ping or a series of pings. The process of water column data collection and analysis is presented in this paper. The proposed method updates the sound speed profile by the automated detection of varying water mass boundaries, giving the option to adjust the SVP for each beam separately. This can increase the overall accuracy of a bathymetric survey and provide additional oceanographic data about the study area.

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
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