Results 81 to 90 of about 3,475,694 (250)

Seasonal Characterisation of Sonar Performance for Effective Underwater Surveillance in the Marmara Sea

IET Radar, Sonar & Navigation
This study analyses sonar performance for underwater object detection in four regions of the Marmara Sea, using oceanographic data from the Turkish Naval Forces and open source datasets.
Murat Murat, Ugur Kesen
doaj   +1 more source

The Effects of Noise on the Juvenile Life Stage of Crustaceans: Behavioral, Cellular, and Molecular Responses in Procambarus clarkii

Integrative Zoology, EarlyView.
Juvenile Procambarus clarkii exposed to noise exhibited behavioral changes, shifts in enzymatic activity, and altered expression of stress and immune genes. The findings highlight the sensitivity of invertebrate juveniles to anthropogenic acoustic pollution.
Maria Ceraulo, Giuseppa Buscaino, Clarissa De Vita, Aiti Vizzini, Mirella Vazzana, Elena Papale, Francesco Longo, Francesco Paolo Faraone, Manuela Mauro   +8 more
wiley   +1 more source

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  

A Small-Sample Target Detection Method of Side-Scan Sonar Based on CycleGAN and Improved YOLOv8

Applied Sciences
Because of their low cost and ease of deployment, side-scan sonars is one of the most widely used underwater survey instruments. However, the complexity of the marine environment and the difficulty in target acquisition limit the detection accuracy of ...
Ye Zheng, Jun Yan, Junxia Meng, Ming Liang   +3 more
doaj   +1 more source

Successful 22‐Hour Rescue and Release of a 19.5 M Beached Sperm Whale

Integrative Zoology, EarlyView.
19.5‐m‐long sperm whale was stranded on a mudflat, China on 19 April 2022. A dramatic 22‐hour rescue mission ultimately saved the whale, enabling it to swim back to sea. ABSTRACT Whales, dolphins, and porpoises are important flagship species and play a vital role in maintaining healthy aquatic ecosystems. However, stranded cetaceans are often doomed if
Zitong Zhou, Yu Pan, Zhi Yang, Fangqiao Wang, Tianshi Wei, Zhitao Wang   +5 more
wiley   +1 more source

Size constancy in bat biosonar? [PDF]

, 2013
Perception and encoding of object size is an important feature of sensory systems. In the visual system object size is encoded by the visual angle (visual aperture) on the retina, but the aperture depends on the distance of the object. As object distance
Heinrich, Melina, Melina Heinrich, Heinrich Melina, Wiegrebe, L., Heinrich, M., Wiegrebe Lutz, Wiegrebe, Lutz, Lutz Wiegrebe   +7 more
core   +2 more sources

UNIQAT: An open‐source toolkit for reproducible image quality assessment in marine surveys

Methods in Ecology and Evolution, EarlyView.
Abstract Modern marine surveys generate tens of thousands of underwater images per expedition, yet many are unusable due to image quality deterioration. Manual quality screening is labour‐intensive, subjective and inconsistent across observers and teams, hindering reproducible science, creating large backlogs of unprocessed imagery, and limiting real ...
Alzayat Saleh, Arjun Chennu
wiley   +1 more source

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  

Sea Bottom Line Tracking in Side-Scan Sonar Images Using WTMM-Based Edge Detection

Journal of Marine Science and Engineering
The topographic features of the seafloor can be observed clearly via high-resolution side-scan sonar imagery. However, the faithful interpretation of a sonar image depends strongly on the accuracy with which the location of the sea bottom line can be ...
Jisheng Ding, Fengbiao Jiang, Fangqi Wang, Long Yang   +3 more
doaj   +1 more source

Distributed acoustic sensing for marine mammal monitoring

Methods in Ecology and Evolution, EarlyView.
Abstract Marine mammal monitoring provides critical data to inform species management and sustainable industrial development. Passive acoustic monitoring, in particular, can provide continuous, long‐term and non‐observer‐biased data, with a subset of systems capable of delivering data in near‐real time.
Léa Bouffaut
wiley   +1 more source