Results 31 to 40 of about 50,747 (268)
L’application de la géophysique marine au diagnostic subaquatique
Archéopages, 2015 The size of the areas that need to be surveyed underwater can quickly get out of hand, which means that traditional survey methods of total survey of the seabed by divers are not up appropriate.
Philippe Pelgas +4 more
doaj +1 more source
Geometrical Spreading Correction in Sidescan Sonar Seabed Imaging
Journal of Marine Science and Engineering, 2017 Sound backscattered to a sonar from a seabed decreases in intensity with increasing range ( R ) due to geometrical spreading. As a far-range approximation, a geometrical spreading correction of + 30 log R decibels may be applied.
Duncan Tamsett
doaj +1 more source
Journal of Marine Science and Engineering, 2016 The backscatter response of a seabed to an incident sonar signal is dependent on the carrier wave frequency: i.e., the seabed is acoustically colourful.
Duncan Tamsett +2 more
doaj +1 more source
Side-scan Sonar Image Segmentation Algorithm Based on Super-pixels Clustering [PDF]
Jisuanji gongcheng, 2018 Traditional super-pixels segmentation method has problems of poor anti-noise performance,inaccurate merging and other issues.To solve these problems,a method of segmentation of side-scan sonar images by super-pixel clustering is proposed.The fast ...
SHENG Yunxia,HUO Guanying,LIU Jing
doaj +1 more source
Pisces IV submersible observations in the epicentral region of the 1929 Grand Banks earthquake [PDF]
, 1989 The PISCES IVsubmersible was used to investigate the upper continental slope around 44 ON, 56 W, near the epicentre of the 1929 Grand Banks earthquake. Four dives in water depths of 800-2000 m were undertaken to observe speci3c features identijied with ...
Hughes Clarke, John E. +3 more
core +2 more sources
Seafloor geodesy from repeated sidescan sonar surveys [PDF]
Journal of Geophysical Research: Solid Earth, 2016 AbstractAccurate seafloor geodetic methods are critical to the study of marine natural hazards such as megathrust earthquakes, landslides, and volcanoes. We propose digital image correlation of repeated shipboard sidescan sonar surveys as a measurement of seafloor deformation. We test this method using multibeam surveys collected in two locales: 2500 m
John B. DeSanto +2 more
openaire +1 more source
Differential Phase Estimation with the SeaMARC II Bathymetric Sidescan Sonar System [PDF]
, 1992 A maximum-likelihood estimator is used to extract differential phase measurements from noisy seafloor echoes received at pairs of transducers mounted on either side of the SeaMARC II bathymetricsidescan sonar system. Carrier frequencies for each side are
Cervenka, Pierre +3 more
core +2 more sources
Inferring depth contours from sidescan sonar using convolutional neural nets
IET radar, sonar & navigation, 2020 Sidescan sonar images are 2D representations of the seabed. The pixel location encodes distance from the sonar and along track coordinate. Thus one dimension is lacking for generating bathymetric maps from sidescan.
Yiping Xie, Nils Bore, J. Folkesson
semanticscholar +1 more source
DSA-SOLO: Double Split Attention SOLO for Side-Scan Sonar Target Segmentation
Applied Sciences, 2022 Side-scan sonar systems play an important role in tasks such as marine terrain exploration and underwater target identification. Target segmentation of side-scan sonar images is an effective method of underwater target detection.
Honghe Huang +4 more
doaj +1 more source
A Curvelet-Transform-Based Image Fusion Method Incorporating Side-Scan Sonar Image Features
Journal of Marine Science and Engineering, 2023 Current methods of fusing side-scan sonar images fail to tackle the issues of shadow removal, preservation of information from adjacent strip images, and maintenance of image clarity and contrast. To address these deficiencies, a novel curvelet-transform-
Xinyang Zhao +5 more
doaj +1 more source