Results 91 to 100 of about 2,798,162 (216)

Area and depth coverage assessment for low-frequency synthetic aperture sonar unexploded ordnance detection surveys

, 2021
44Low frequency synthetic aperture sonar (LF-SAS) is a key technique for the detection and characterization of unexploded ordnance (UXO) in the underwater environment. For buried UXO, however, it is rather difficult to determine the range and depth up to
Beckers, A.L.D., Vossen, R. van, Mulders, I., Duijster, A.J., Burg, D. van der, Sande, J.J.M. van de   +5 more
core  

Low frequency continuous active sonar

, 2011
Existing sonar systems are commonly deployed at a low duty cycle, i.e. a short transmit signal is used followed by a long listening time. As a result, the target is only illuminated during a short time resulting in only one detection opportunity per ping.
Vossen, R. van, Spek, E. van der, Beerens, S.P.   +2 more
core  

Behavioural Diversity of Fishes: Concepts, Drivers and Its Role in Conservation and Management

Fish and Fisheries, EarlyView.
ABSTRACT Human activity has altered nearly all ecosystems on Earth, contributing to substantial biodiversity loss across taxonomic, genetic and functional dimensions, from the intraspecific to the ecosystem scale. Yet some components of biodiversity remain hidden or underappreciated, including behavioural diversity.
Marie Prchalová, Robert Arlinghaus, Samuel Westrelin, Ivan Jarić, Michael G. Bertram, Josep Alós, Henrik Baktoft, Jack A. Brand, Tomas Brodin, Adolfo Cordero‐Rivera, Carlina Feldmann, Ryo Futamura, Stefan Hont, Pascal Klamser, Cecilie Iden Nilsen, Johann Mourier, Karl Øystein Gjelland, Esben Moland Olsen, Polona Pengal, Rubén Rabaneda‐Bueno, Milan Říha, Theresa Rueger, Holger Schielzeth, Marco Signaroli, Marija Smederevac‐Lalić, Christopher T. Monk   +25 more
wiley   +1 more source

Principles of Sonar Performance Modeling

, 2010
Sonar performance modelling (SPM) is concerned with the prediction of quantitative measures of sonar performance, such as probability of detection. It is a multidisciplinary subject, requiring knowledge and expertise in the disparate fields of underwater
Ainslie, M.A.
core  

Robust Multiping Forward-Looking Sonar Coherent Detection

We tackle the problem of adaptive multiping detection of quasi-static point-like targets by moving forward-looking sonar based on the principles of coherent imaging.
Matte, Guillaume, Ginolhac, Guillaume, Mian, Ammar, Ovarlez, Jean-Philippe, Charlot, Didier, Lerda, Olivier   +5 more
core   +1 more source

Studies into the detection of buried objects (particularly optical fibres) in saturated sediment. Part 4: experimental investigations into the acoustic detection of objects buried in saturated sediment

, 2007
This report is the fourth in a series of five, designed to investigate the detection oftargets buried in saturated sediment, primarily through acoustical or acoustics-relatedmethods.
Evans, R.C.P.
core   +1 more source

Examining the Impact of Derelict Pots on Blue Crab (Callinectes sapidus) Catch and Harvest Within a Recreational Fishery

Fisheries Management and Ecology, EarlyView.
ABSTRACT Derelict fishing gear can negatively affect marine ecosystems through mortality in coastal environments. This study explored the impact of derelict and active crab pots on recreational blue crab (Callinectes sapidus) catch rates and landings in a Mid‐Atlantic estuary by deploying experimental pots in four habitat strata within three sections ...
Randy J. Feris Serrano, Jennifer E. Repp, Kaylin M. Regan, Arthur C. Trembanis, Matthew J. Oliver, Edward A. Hale   +5 more
wiley   +1 more source

DCE-Net: An Improved Method for Sonar Small-Target Detection Based on YOLOv8

Journal of Marine Science and Engineering
Sonar is the primary tool used for detecting small targets at long distances underwater. Due to the influence of the underwater environment and imaging mechanisms, sonar images face challenges such as a small number of target pixels, insufficient data ...
Lijun Cao, Zhiyuan Ma, Qiuyue Hu, Zhongya Xia, Meng Zhao   +4 more
doaj   +1 more source

Multitrophic responses to tidal marsh restoration: early effects of channel configuration on water quality, aquatic food web structure, and fish communities

Restoration Ecology, EarlyView.
Abstract Introduction Tidal wetland restoration is critical for reversing habitat loss and enhancing resilience under sea‐level rise and climate variability. Dutch Slough in the San Francisco Estuary served as a living laboratory for adaptive management.
Joseph E. Merz, Cheryl Dean, Bobbie Flores, Katie Karpenko, Kai Ross, Andrew Veary   +5 more
wiley   +1 more source

Early results and lessons learned from biomanipulation and chemical restoration of a eutrophic shallow lake

Restoration Ecology, EarlyView.
Abstract Introduction Over 44% of European lakes fail to meet ecological quality standards, prompting substantial investment in lake restoration to achieve good ecological status. Unfortunately, effects are often short‐lived due to persistent internal phosphorus (P) loading and strong cyprinid‐driven bottom‐up control, which limits water quality ...
Emma Polauke, Kaj Sand‐Jensen, Christian Skov, Theis Kragh   +3 more
wiley   +1 more source