Environmental impact on active‐sonar performance predictions in shallow water

In shallow water the acoustic wave from ambient noise sources carries a large number of environment information based on the complicated reflection both on the surface and seabed interface. The sound speed profile is one of the influencing factors of sound propagation characteristic, while for a long distance the sound absorption coefficient of water medium has an important significance to propagation range. The simulation results show that in shallow water sound absorption of seabed, sound speed profile and sound absorption of water were taken into account, then range prediction of active sonar can be exactly obtained using normal-mode propagation.

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Automatic detection and tracking of a small surface watercraft in shallow water using a high-frequency active sonar

IEEE Transactions on Aerospace and Electronic Systems ◽

10.1109/taes.2004.1386890 ◽

2004 ◽

Vol 40 (4) ◽

pp. 1377-1388 ◽

Cited By ~ 6

Author(s):

K.W. Lo ◽

B.G. Ferguson

Keyword(s):

Shallow Water ◽

High Frequency ◽

Automatic Detection ◽

Small Surface ◽

Active Sonar ◽

Detection And Tracking

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Economic impact of aquaculture in floodplains - a case study of Sonmar Chaur in Bihar, India

Indian Journal of Fisheries ◽

10.21077/ijf.2016.63.3.41676-14 ◽

2016 ◽

Vol 63 (3) ◽

Cited By ~ 1

Author(s):

Raushan Kumar ◽

Nalini Ranjan Kumar ◽

P. K. Katiha ◽

M. Krishnan ◽

Satya Prakash ◽

...

Keyword(s):

Environmental Impact ◽

Impact Assessment ◽

Shallow Water ◽

Marketing Channels ◽

Water Bodies ◽

Fish Production ◽

Small Holders ◽

Employment Generation ◽

Limited Scope

Chaurs are shallow water logged areas and have limited scope for agriculture, but can be better utilised for agriculture cum fish production. About 70% (28.34 ha) area of Sonmar chaur in Bihar has been converted into small ponds for aquaculture purposes. Income and employment generated from the chaur from both agriculture and fisheries and fish disposal pattern were studied. The study revealed aquaculture as most profitable enterprise `3,28,000 ha-1) with BC ratio 1.46 followed by agriculture (`37,900 ha-1) and culture based fisheries (`34,400 ha-1) with B-C ratio 2.1 and 2.6, respectively. Maximum employment was generated from aquaculture (1411 man days ha-1) followed by culture based fisheries (70 man days ha-1) and agriculture (35 man days ha-1). The higher employment generation in culture fisheries was mainly due to requirement for watch and ward. The fish was sold either directly to the ultimate consumers or through the vendors. Among the two marketing channels operatings Channel-I in which producer sells directly to consumers was found more efficient (69.7). Though, aquaculture was more profitable and generated higher employment, it requires much higher resources for its practice which may hinder small holders to adopt such practice and also it may impact certain indirect uses of these water bodies. Environmental impact assessment and support to small farmers are needed to utilise such water bodies through aquaculture.

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A method to predict active sonar detection range in uncertain shallow water environments

The Journal of the Acoustical Society of America ◽

10.1121/1.4786870 ◽

2006 ◽

Vol 119 (5) ◽

pp. 3426-3426

Author(s):

Peter G. Cable

Keyword(s):

Shallow Water ◽

Detection Range ◽

Active Sonar

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