Results 21 to 30 of about 10,692 (214)

Vertical dimension acoustic field interference pattern prediction and source depth estimation in deep ocean [PDF]

JASA Express Letters
In this Letter, a simplified expression of the vertical dimension narrowband interference pattern in deep water direct arrival zone is theoretically derived. The correlation between the vertical dimension interference pattern and source depth is analyzed,
Guangying Zheng, Hao Wang, Shuaishuai Zhang, Linlang Bai, Fangwei Zhu, Jiabao Feng, Wang Hao   +6 more
doaj   +1 more source

Adaptive Hoyer-L-Moment Envelope Spectrum: A Method for Robust Demodulation of Ship-Radiated Noise in Low-SNR Environments

Sensors
Propeller noise is the main source of ship-radiated noise. Extracting and analyzing the modulation characteristics from the propeller noise plays a crucial role in classifying and identifying vessel targets.
Ruizhe Zhang, Qingcui Wang, Shuanping Du
doaj   +1 more source

Active sonar target recognition method based on multi‐domain transformations and attention‐based fusion network

IET Radar, Sonar & Navigation
The classification and recognition of underwater targets by an active sonar system remain challenging and complex. Traditional methods have limited classification performance in time and spatially varying ocean channels.
Qingcui Wang, Shuanping Du, Wei Zhang, Fangyong Wang   +3 more
doaj   +1 more source

Interpreting How Neural Networks Infer Scatterer Geometry from Echolocation Echoes

Advanced Intelligent Systems, EarlyView.
Neural networks enable echolocation‐based shape classification but remain difficult to interpret due to their black‐box nature. This work presents a feature‐importance metric to uncover the echo regions driving decisions in shape‐specialized networks.
Ganesh U. Patil, Hyung‐Suk Kwon, Bogdan‐Ioan Popa   +2 more
wiley   +1 more source

Matched cross‐spectrum phase processing for source depth estimation in deep water

IET Radar, Sonar & Navigation
Zhou et al. (2022) proposed a method for instantaneous source depth estimation in deep water using matched beam intensity processing (MBIP) that leverages depth‐related oscillatory features arising from Lloyd's mirror interference in the frequency domain
Lisheng Zhou, Xiaohong Yang, Guangying Zheng, Fangwei Zhu, Fangyong Wang   +4 more
doaj   +1 more source

Simulated Research on Passive Sonar Range Using Different Hydrographic Conditions

MATEC Web of Conferences, 2015
As an example using the passive sonar, it calculated the quality factor of passive sonar using the sonar equation. The sound field was calculated under different depth and range using multiform hydrographic conditions.
Han Jing, Zhang XueGang, Meng ChunXia, Cao Feng   +3 more
doaj   +1 more source

Inference of Bubble Size Distribution in Sediments Based on Sounding by Chirp Signals

Archives of Acoustics
A method is proposed to estimate the bubble void fraction and bubble size distribution in marine sediments based on measured sound speed and attenuation data in gas-bearing sediments.
Xiaohong YANG, Guangying ZHENG, Fangyong WANG, Fangwei ZHU, Linlang BAI   +4 more
doaj   +1 more source

Study on the Classification Performance of Underwater Sonar Image Classification Based on Convolutional Neural Networks for Detecting a Submerged Human Body

Sensors, 2019
Auto-detecting a submerged human body underwater is very challenging with the absolute necessity to a diver or a submersible. For the vision sensor, the water turbidity and limited light condition make it difficult to take clear images.
Huu-Thu Nguyen, Eon-Ho Lee, Sejin Lee
doaj   +1 more source

Optimizing Strategies for Non‐Invasive Prospection of Settlements in the Intertidal Zone: A Case Study From the Centre of the Drowned Medieval Village of Tolsende (Scheldt Estuary, the Netherlands)

Archaeological Prospection, EarlyView.
ABSTRACT Medieval and early modern drowned villages in the intertidal zone of the Scheldt estuary (the Netherlands) constitute intriguing yet largely understudied components of north‐western Europe's underwater cultural heritage. Despite their high archaeological potential as time capsules of past settlement landscapes, research has remained limited ...
Jan Trachet, Sarah Bäumler, Stefan Krojer, Jeroen Verhegge, Wim De Clercq, Philippe De Smedt, Wouter H. Maes, Bente S. Majchczack, Immo Trinks, Dennis Wilken   +9 more
wiley   +1 more source

Investigation and Numerical Simulation of the Acoustic Target Strength of the Underwater Submarine Vehicle

Inventions, 2022
Modern weapon systems’ survival hinges on their detection capabilities more than anything else. In the active sonar equation, the acoustic target strength is crucial.
Kaveripakam Sathish, Rajesh Anbazhagan, Ravikumar Chinthaginjala Venkata, Fabio Arena, Giovanni Pau   +4 more
doaj   +1 more source