Results 21 to 30 of about 425,127 (302)

Parameter Estimation for Multi-Scale Multi-Lag Underwater Acoustic Channels Based on Modified Particle Swarm Optimization Algorithm

IEEE Access, 2017
The wideband underwater acoustic multipath channel can be modeled as a multi-scale multi-lag (MSML) channel because signals from different paths might experience different Doppler scales. This brings great challenge to channel parameter estimation.
Xing Zhang, Kang Song, Chunguo Li, Luxi Yang   +3 more
doaj   +1 more source

Dynamic Optimization Method for Broadband ADCP Waveform with Environment Constraints

Sensors, 2021
Broadband acoustic Doppler current profiler (ADCP) is widely used in agricultural water resource explorations, such as river discharge monitoring and flood warning.
Yongshou Yang, Shiliang Fang
doaj   +1 more source

Blind Estimation of the PN Sequence of A DSSS Signal Using A Modified Online Unsupervised Learning Machine

Sensors, 2019
Direct sequence spread spectrum (DSSS) signals are now widely used in air and underwater acoustic communications. A receiver which does not know the pseudo-random (PN) sequence cannot demodulate the DSSS signal.
Yangjie Wei, Shiliang Fang, Xiaoyan Wang, Shuxia Huang   +3 more
doaj   +1 more source

Improved Velocity Estimation Method for Doppler Sonar Based on Accuracy Evaluation and Selection

Journal of Marine Science and Engineering, 2021
The matched filtering method and the waveform-tracking method cannot maintain optimal velocity estimation performance all of the time. In order to solve this problem, this paper proposes an improved velocity estimation method for Doppler sonar, based on ...
Yongshou Yang, Shiliang Fang
doaj   +1 more source

Underwater Acoustic Detection of Ultra High Energy Neutrinos

, 2005
We investigate the acoustic detection method of 10^18-20 eV neutrinos in a Mediterranean Sea environment. The acoustic signal is re-evaluated according to dedicated cascade simulations and a complex phase dependant absorption model, and compared to ...
Aguilar, Alvarez-Muniz, Alvarez-Muniz, Anthony, Askariyan, Askariyan, Bertou, Blankenbecler, Brown, Dedenko, Feldman, Fletcher, Francois, Gandhi, Glashow, Gorham, Greisen, Greisen, Hansen, Hotta, Knudsen, Landau, Landau, Learned, Lehtinen, Liebermann, Migdal, Nagano, Smirnov, Stanev, Sulak, Urick, V. Bertin, V. Niess, Waxman, Zaptsepin   +35 more
core   +3 more sources

Parameter Estimation of Delay-Doppler Underwater Acoustic Multi-Path Channel Based on Iterative Fractional Fourier Transform

IEEE Access, 2019
The characterization of wideband underwater acoustic (UWA) multi-path signals is investigated in this paper. The UWA multi-path channel can be considered as a sparse model and it causes changes of the transmitted signal on Doppler factor, time delay, and
Shuxia Huang, Shiliang Fang, Ning Han
doaj   +1 more source

From Informed Independent Vector Extraction to Hybrid Architectures for Target Source Extraction

IEEE Open Journal of Signal Processing
This article revises informed independent vector extraction (iIVE) as a framework for connecting model-based blind source extraction (BSE) with deep learning. We introduce the contrast function for iIVE, which is derived by extending IVE with beamforming-
Zbynek Koldovsky, Jiri Malek, Martin Vratny, Tereza Vrbova, Jaroslav Cmejla, Stephen O'Regan   +5 more
doaj   +1 more source

Three-Dimensional Non-Uniform Sampled Data Visualization from Multibeam Echosounder Systems for Underwater Imaging and Environmental Monitoring

Remote Sensing
This paper proposes a method for visualizing three-dimensional non-uniformly sampled data from multibeam echosounder systems (MBESs), aimed at addressing the requirements of monitoring complex and dynamic underwater flow fields.
Wenjing Cao, Shiliang Fang, Chuanqi Zhu, Miao Feng, Yifan Zhou, Hongli Cao   +5 more
doaj   +1 more source

Limitations and Performance Analysis of Spherical Sector Harmonics for Sound Field Processing

Applied Sciences
Developing spherical sector harmonics (SSHs) benefits sound field decomposition and analysis over spherical sector regions. Although SSHs demonstrate potential in the field of spatial audio, a comprehensive investigation into their properties and ...
Hanwen Bi, Shaoheng Xu, Fei Ma, Thushara D. Abhayapala, Prasanga N. Samarasinghe   +4 more
doaj   +1 more source

A Nonlinear Data-Driven Towed Array Shape Estimation Method Using Passive Underwater Acoustic Data

Remote Sensing, 2022
Large-aperture towed linear hydrophone array has been widely used for beamforming-based signal enhancement in passive sonar systems; however, its performance can drastically decrease due to the array distortion caused by rapid tactical maneuvers of the ...
Qisong Wu, Youhai Xu
doaj   +1 more source