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The draft design for a new apparatus to study sediment transport processes in shallow water is described. This design was subjected to analysis using computational fluid dynamics (CFD) to ensure that it performed satisfactorily in both tidal and wave-induced flows. The analyses indicated that performance could be improved by minor modifications to the design, particularly to the design of the flow-sensor...
Against the background of an increasing demand for fish products and shrinking natural resources, producing fish in aquaculture plants is already an important economical and ecological factor. Keeping this in mind we therefore suggest a novel pond-in-pond aquaculture plant is being developed within the frame of the Aqualnno project which was funded by German Federal Ministry of Economics and Technology...
Detection and classification of underwater mines with synthetic aperture sonar (SAS) images is a challenge that can be performed in studying either the echoes or the shadows of mines. But, as any images obtained with a coherent system, SAS images are highly corrupted by the speckle noise, which reduces spatial and radiometric resolutions. So such a noise can be very disturbing for the interpretation...
In this paper several key issues in supervised learning using artificial neural networks are addressed within an ASW barrier operation framework. Training data distribution, input space representation, parameters variations, signal excess fluctuations and agents behaviors have a great influence on the neural network controlled submarine performance and tactics. A qualitative sensitivity analysis of...
The motion of a simple inertial wave energy converter (WEC) is studied to find the relative motion between an internal mass and an external body. The power take off (PTO) system is deemed to connect the internal mass to the external body, modelled as a spring and damper in parallel. This PTO system is assumed to have both linear and nonlinear components, since this will result in a more accurate model...
Autonomous underwater vehicles (AUV) are expected to perform survey missions in both known and unknown environments. While the primary mission of an AUV is data collection, generally achieved with a sidescan sonar or a multibeam echosounder, another key task is to guaranty its own security. This paper deals with the problem of obstacle detection and avoidance by means of a forward looking sonar (FLS)...
The major goal of this project, elaborated in the frame of the STREP Exocet/D European project, was to design a first autonomous long-term imaging module equipped with a deep-sea video camera, adequate lightning and sufficient energy storage while taking advantage of most recent progress in imaging and photonics. The new ecological module TEMPO was tested and deployed during the Momareto cruise held...
ESONET is an European Network of Excellence (NoE) associating 50 partners (research centres, universities, industrials and SMEs) from 14 countries: France, Germany, Italy, UK, Spain, Portugal, Greece, Belgium, Ireland, the Netherlands, Norway, Sweden, Bulgaria and Turkey. More than 300 scientists and engineers will participate to its activities. The goal of the ESONET NOE is the lasting integration...
To deliver high power and broadband communication to the ocean floor requires a number of changes to existing technology developed to bridge oceans from shore to shore. The dry-dry solution is well mastered and although it evolves over time following technological innovations, adapting it to become a dry-wet solution represents a major technical challenge. The cabled observatory system developed for...
The effects that particulate and coloured dissolved materials had on the underwater light field were examined using a combination of in situ observations and radiance transfer modelling. Hydrolight (a commercially available radiance transfer software program) was used to validate in situ measurements of inherent optical properties (IOPs). A general set of specific optical cross sections were derived...
In this paper a towed semi-autonomous system for automatic tracking of underwater pipeline is presented together with some experimental tests of the pipeline sensing apparatus. This paper focuses, in particular, on the development of a new guidance system based on the differential magnetometers which is the output measurements in the feedback loop.
The Commander Naval Meteorology and Oceanography Command (COMNAVMETOCCOM) manages a scope of activities that sponsor, create, operate, and maintain capabilities that support the operational goals of Naval Meteorology and Oceanography (METOC). Effective and efficient Naval METOC operations require partnerships and collaborations within the U.S. Navy, with external U.S. Department of Defense (DoD) and...
This paper discusses the development and use of novel glass and polymer tracers, based on narrow band atomic fluorescence, which have been developed for deployment as environmental tracers. The use of discrete fluorescent species in an environmentally stable host has been developed to replace existing toxic, broad band molecular dye tracers. The narrow band emission signals offer the potential for...
Like any other ad-hoc network, an underwater communication network (UWCN) is a collection of nodes (we have assumed a large number), each of which is initially unaware of the existence of other nodes. Often, it is desirable for each node to be able to estimate the number of neighbours (i.e., the number of directly visible nodes) with which it can communicate. This paper provides a probabilistic estimation...
In January 2006, a juvenile female bottlenosed whale became trapped in the Thames in the centre of London. The event attracted international interest. Rescue of the whale was attempted but failed. This paper describes these events and discusses the role of underwater sound in whale navigation. The effect of high-energy waveguide modified signals producing whale-like signatures capable of inducing...
This paper presents an Automated Change Detection and Classification (ACDC) System, developed by the Naval Research Laboratory (NRL) and the Naval Oceanographic Office (NAVOCEANO), which aids analysts in performing change detection in real-time (RT) by co-registering new and historical imagery and using automated change detection algorithms that suggest imagery changes. In this paper, ACDC-RT components...
Marine mammals are used increasingly as a vehicle through which environmental compliance is measured. The special status of marine mammals within both statute and public opinion are built upon a foundation of knowledge about the utility of marine mammals as indicators of marine environmental state. Quantifying the risk to marine mammals is therefore an important part of the environment assessments...
During early August 2006, a series of meteorological and near surface oceanographic measurements (-0-200 m) were conducted from R/V Mt. Mitchell in an ocean region in the northeast Pacific, near 46degN, 126deg W, west of the North America continental shelf break, and in 2000 m deep water. The test region was roughly 20 nmi west of the main path of the California Current, however, observations of a...
The remotely operated vehicle (ROV) Kaiko, built in 1995, is able to dive at ocean depths of 11,000 m. On May 29, 2003. the Kaiko's secondary cable snapped, and the Kaiko's vehicle has been missing. JAMSTEC (Japan Agency for Marine-Earth Science and Technology) was decided to remodel the 7,000 m class ROV UROV7K instead of the lost vehicle in order to continue the scientific activities. This system...
The aim of this paper is to obtain a parametric models of manoeuvring for an in-scale fast-ferry model, TF-120. This model is autonomous and is controlled remotely from a PC using Wi-Fi communications. The tests with the autonomous in-scale physical model of the high-speed ship were carried out in the surroundings of the Bay of Santander.
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