Doppler spreading of aircraft harmonics in a shallow‐water channel off Kauai

2006 ◽  
Vol 120 (5) ◽  
pp. 3181-3181
Author(s):  
David Barclay ◽  
Michael J. Buckingham
Keyword(s):  
Shallow Water ◽  
Water Channel

Measurements of signal coherence for high and low duty cycle sonars in a shallow water channel

2015 ◽  
Author(s):  
Paul C. Hines ◽  
Keaton Hicks ◽  
Stefan M. Murphy ◽  
Nicholas Taylor
Keyword(s):  
Shallow Water ◽  
Duty Cycle ◽  
Water Channel ◽  
Low Duty Cycle

Experimental Multipath Delay Profile of Underwater Acoustic Communication Channel in Shallow Water

2016 ◽  
Vol 2 (2) ◽  
pp. 351 ◽  
Author(s):  
Yasin Yousif Al_Aboosi ◽  
Ahmad Zuri Sha'ameri
Keyword(s):  
Shallow Water ◽  
Acoustic Communication ◽  
Multipath Propagation ◽  
Water Channel ◽  
Underwater Acoustic Communication ◽  
Communication Performance ◽  
Underwater Acoustic ◽  
Research Fields ◽  
Different Depths ◽  
Major Factors

<p>The shallow water channel is an environment that is of particular interest to many research fields. An underwater acoustic channel is characterized as a multipath channel. Time-varying multipath propagation is one of the major factors that limit the acoustic communication performance in shallow water. This study conducts two underwater acoustic experiments in Tanjung Balau, Johor, Malaysia. A transducer and a hydrophone are submerged at different depths and separated by different distances. Linear frequency modulated (LFM) pulses are chosen as the main transmit signal for the experiments. The cross-correlation between the transmitted and received signals represents the impulse response of the channel (multipath profile). The results show that the amplitude of the successive paths will not rapidly decline, and vice versa, when the distance between the sender and the receiver increases. Moreover, the time difference between the different paths will be small in the case of distance increase. In other words, the successive paths will converge in time.</p>

The Dependence of Signal Coherence on Sea-Surface Roughness for High and Low Duty Cycle Sonars in a Shallow-Water Channel

2017 ◽  
Vol 42 (2) ◽  
pp. 298-318 ◽  
Author(s):  
Paul C. Hines ◽  
Stefan M. Murphy ◽  
Douglas A. Abraham ◽  
Grant B. Deane
Keyword(s):  
Surface Roughness ◽  
Shallow Water ◽  
Duty Cycle ◽  
Water Channel ◽  
Sea Surface ◽  
Sea Surface Roughness ◽  
Low Duty Cycle

scholarly journals Recurrent networks for direction-of-arrival identification of an acoustic source in a shallow water channel using a vector sensor

2021 ◽  
Vol 150 (1) ◽  
pp. 111-119
Author(s):  
Steven Whitaker ◽  
Andrew Barnard ◽  
George D. Anderson ◽  
Timothy C. Havens
Keyword(s):  
Shallow Water ◽  
Water Channel ◽  
Direction Of Arrival ◽  
Recurrent Networks ◽  
Acoustic Source ◽  
Vector Sensor

scholarly journals Hybrid time synchronization for Underwater Sensor Networks

ACTA IMEKO ◽  
2015 ◽  
Vol 4 (3) ◽  
pp. 30
Author(s):  
Oriol Pallares Valls ◽  
Pierre-Jean Bouvet ◽  
Joaquí­n Del Rí­o
Keyword(s):  
Shallow Water ◽  
Time Synchronization ◽  
Water Channel ◽  
Distributed Applications ◽  
Underwater Sensor Networks ◽  
Critical Part ◽  
Communication Challenges ◽  
Hybrid Synchronization ◽  
Simulation Results ◽  
Synchronization Problems

<p>Time synchronization is a critical part of distributed applications over a sensor network. In this work we investigate time synchronization problems over UWSN deployed in shallow water, taking into account all main communication challenges of the water channel and observing its behavior in simulation and real tests. A hybrid frame was proposed based on time synchronization using both LFM and OFDM communication with channel impulse response equalization. Simulation results show how Hybrid synchronization outperforms existing synchronization protocols and how these results are affected in real underwater tests.</p>

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