Results 51 to 60 of about 48,682 (230)

Uncertainty assessment for a novel optically shallow water radiometric acquisition platform

Limnology and Oceanography: Methods, EarlyView.
Abstract We present a novel motorized platform, a custom‐built jet‐ski designed for acoustic and radiometric measurements in optically shallow coastal waters. This platform integrates in‐water radiometers with single‐beam and multi‐beam acoustic sensors, along with a suite of active and passive instruments (conductivity‐temperature‐depth, fluorescence,
Raphaël Mabit, Simon Bélanger, Pascal Bernatchez   +2 more
wiley   +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

Influence of Beam Angle of Array Sound Source on Sound Propagation in Typical Shallow Sea Environments

水下无人系统学报
With the development of active sonar technology, the beam output capability of active sonar has become the focus of engineering research. It is necessary to study the influence of the sound beam angle on sound propagation for a typical vertical linear ...
Yanyang LU, Qinglang CHEN, Xun LI, Zhaohong WANG   +3 more
doaj   +1 more source

Impact of data assimilation on Arctic sea‐ice thickness variability and its coupling with atmospheric forcing

Quarterly Journal of the Royal Meteorological Society, EarlyView.
We document for the first time how the assimilation of CS2SMOS observations improves the model representation of Arctic sea‐ice thickness (SIT) and its variability: biases are reduced (top row), while excessive variability in the Beaufort Sea and lack of variability in the ice pack are both corrected (bottom row).
Jiping Xie, Yue Ying, Richard Davy, Laurent Bertino   +3 more
wiley   +1 more source

Research on the Distance of the Active Sonar under the Effects of the Thermocline

Journal of Measurement Science and Instrumentation, 2010
The existence of thermocline changes the acoustic structure and effects the direction of the sound rays.This paper analyzes the working process of the active sonar,and the mathematical models.The detection probability of the active sonar under ...
Xian-ku ZHANG, Ji-duan LI
doaj  

Coherent and Noncoherent Joint Processing of Sonar for Detection of Small Targets in Shallow Water

Sensors, 2018
A coherent-noncoherent joint processing framework is proposed for active sonar to combine diversity gain and beamforming gain for detection of a small target in shallow water environments.
Xiang Pan, Jingning Jiang, Si Li, Zhenping Ding, Chen Pan, Xianyi Gong   +5 more
doaj   +1 more source

Autonomous Navigation in Large‐Scale Underground Environments Based on a Purely Topological Understanding of Tunnel Networks

Journal of Field Robotics, EarlyView.
ABSTRACT This work presents a non‐geometrical navigation approach based on a purely topological understanding of underground environments. By conceptualizing subterranean scenarios as a set of tunnels that intersect with each other, and taking a navigation approach based on topological instructions, we simplify the navigation problem to the sequential ...
Lorenzo Cano, Danilo Tardioli, Alejandro R. Mosteo   +2 more
wiley   +1 more source

Research advances and development trends in acoustic target detection

Zhongguo Jianchuan Yanjiu
Underwater target detection faces severe challenges due to the enhanced acoustic stealth capabilities of targets and the anomalous sound propagation phenomena within complex ocean waveguides.
Yixin YANG, Lei XIE, Long YANG, Yong WANG, Lu WANG, Yuqi LIU   +5 more
doaj   +1 more source

Efficacy and Residue Comparisons between Two Slow-release Formulations of Fluridone [PDF]

, 2003
Residue profiles and efficacy of Avast and Sonar, two slow release pellet formulations of fluridone {1-methyl-3-phenyl-5- [3-(trifluoromethyl)phenly]-4(1H)-pyridinone}, were compared in outdoor tanks. Hydrilla (Hydrilla verticillata (L.f.) Royle) and
Haller, W. T., Koschnick, Tyler J., Santra, U., Vandiver, V. V.   +3 more
core  

Calibration of multibeam echo sounders: a comparison between two methodologies [PDF]

, 2012
Multibeam echo sounders (MBES) are widely used in applications like seafloor imaging, fisheries, and habitat mapping. Calibration of acoustic backscatter is an important aspect of understanding and validating the performance of a MBES.
Lanzoni, Carlo, Weber, Thomas C.
core   +2 more sources