Results 31 to 40 of about 18,223 (315)

Speckle Noise Reduction in Sonar Image Based on Adaptive Redundant Dictionary

Journal of Marine Science and Engineering, 2020
As acoustic waves are affected by the channel characteristics, such as scattering and reverberation when propagating in water, sonar images often exhibit speckle noise which will cause visual quality of the image to decrease.
Yifan Huang, Weixiang Li, Fei Yuan
doaj   +1 more source

ECRKQ: Machine Learning-Based Energy-Efficient Clustering and Cooperative Routing for Mobile Underwater Acoustic Sensor Networks

IEEE Access, 2021
The dynamic topology, narrow transmission bandwidth, and limited energy of sensor nodes in mobile underwater acoustic sensor networks (UASNs) pose challenges to design an efficient and robust network for underwater communications.
Jianying Zhu, Yougan Chen, Xiang Sun, Jianming Wu, Zhenwen Liu, Xiaomei Xu   +5 more
doaj   +1 more source

Underwater Wireless Communications

Sensors
Effective underwater wireless communications (UWCs) are essential for a variety of military and civil applications, such as submarine communication and discovery of new natural resources in the underwater environment [...]
Hamada Esmaiel, Haixin Sun
openaire   +3 more sources

Node Energy Consumption Balanced Multi-Hop Transmission for Underwater Acoustic Sensor Networks Based on Clustering Algorithm

IEEE Access, 2020
With the advancement and implementation of marine strategies in various countries, it is of great significance to collect marine data by using underwater acoustic sensor networks (UWA-SNs).
Meihuang Wang, Yougan Chen, Xiang Sun, Fanggui Xiao, Xiaomei Xu   +4 more
doaj   +1 more source

MF-HER: Marine Mammal-Friendly Based High Spectral-Efficient Routing for Underwater Acoustic Sensor Networks

IEEE Access, 2020
In real ocean environments, artificial acoustic and natural acoustic systems are coexisted to share scarce spectrum resources. In this paper, we propose a marine mammals-friendly based high spectral-efficient routing (MF-HER) protocol to improve spectrum
Yougan Chen, Xinrui Zhang, Xiang Sun, Yi Tao, Xiaomei Xu   +4 more
doaj   +1 more source

Sound Reception in the Yangtze Finless Porpoise and Its Extension to a Biomimetic Receptor

Biomimetics, 2023
Sound reception was investigated in the Yangtze finless porpoise (Neophocaena phocaenoides asiaeorientalis) at its most sensitive frequency. The computed tomography scanning, sound speed, and density results were used to develop a three-dimensional ...
Zhongchang Song, Wenzhan Ou, Jiao Li, Chuang Zhang, Weijie Fu, Wenjie Xiang, Ding Wang, Kexiong Wang, Yu Zhang   +8 more
doaj   +1 more source

Analysis of causation of loss of communication with marine autonomous systems: a probability tree approach [PDF]

, 2014
The last decade has seen the eagerly anticipated introduction of marine autonomous systems as a pragmatic tool for ocean observation. However, outstanding reliability problems means that these vehicles are not yet fulfilling their true potential.
Brito, M.P., Griffiths, G., Smeed, D.A.
core   +1 more source

Channel modeling for underwater optical communication [PDF]

2011 IEEE GLOBECOM Workshops (GC Wkshps), 2011
We consider in this paper channel modeling for underwater optical channels. In particular, we focus on the channel impulse response and quantify the channel time dispersion under different conditions of water type, link distance, and transmitter/receiver parameters.
Chadi Gabriel, Mohammad Ali Khalighi, Salah Bourennane, Pierre Léon, Vincent Rigaud   +4 more
openaire   +3 more sources

Laser based underwater communication systems [PDF]

2016 18th International Conference on Transparent Optical Networks (ICTON), 2016
We report on recent progress in the field of visible light communications including direct modulation of blue laser devices at data rates beyond 10 Gbit/s, and the transmission of 2.5 Gbit/s OOK data through water. We also discuss the advantages of operating with single mode laser devices and matched filtering at the receiver in the context of ...
Giuliano, Giovanni, Viola, Shaun, Watson, Scott, Laycock, Leslie, Rowe, Duncan, Kelly, Anthony E.   +5 more
openaire   +1 more source

Spectral characterisation of shortened pulse position modulation format [PDF]

, 2010
Shortened pulse position modulation (SPPM) is a new modulation format that has recently been proposed for underwater wireless optical communications. A full spectral characterisation of SPPM is considered and original expressions are presented, which ...
Cryan, R.A.
core   +1 more source