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The last generation of autonomous underwater vehicles (AUV) is being developed with intervention capabilities in mind. These capabilities will provide easy and early inspection and maintenance of subsea offshore structures. The technology developments that implies this upgrade comprise new techniques for subsea vehicle localization, including detection and estimation algorithms. A reliable technique...
This paper gives an overview of the AUV-framework, a simulation environment for the evaluation of concepts regarding AUVs. An infrastructure of functionalities (maps, interface to kinematics, communication between multiple AUVs) supports the development of autonomous control.
11,000 m class ROV, KAIKO, was developed in 1995 and dived to the seabed of 11,000 m depth at Challenger Deep in Mariana Trench about 20 times (Fig.1). In March, 1996, KAIKO was sampling almost 20 ml of sediment at Challenger Deep (10,897 m depth). Many microbe in deep sea like extreme environments have been found in it, and their life have been cleared by the little sediment sample. So, it is necessary...
As human population and the demands of better standards of life increase in the 21st century, a sudden surge in energy demand is predicted and the accompanying environmental problems will become a subject of discussion. The establishment of an energy system that uses renewable energy is attracting attention as a possible answer to these problems. This article presents a discussion on one energy harvesting...
The Japan Agency for Marine-earth Science and Technology is now developing an automatic bottom inspection and sampling mobile, ABISMO, which is a full depth rating remotely operated vehicle for conducting research at the deepest sea bottom, observing the area with a camera, and sampling the bottom layer.
An extended Kalman filter (EKF) is proposed to estimate the frequencies and chirp rate of multiple superimposed chirped pulses. The estimation problem is a difficult one, where maximum likelyhood methods are very complex especially if more than two pulses are superimposed. It is shown that for the EKF an arbitrary number of pulses can be tracked, and it will be shown that for the case of two superimposed...
The paper overviews the performances of the HF radar network installed in the northern Adriatic Sea. The system architecture is designed to work in real-time and delayed modes, but the accent is given on the real-time data acquisition, processing, archiving and presenting on the web. Several minor and the major dropout of the system were reported in 2008, and the surface currents were available for...
In the aftermath of the disastrous Indonesian Tsunami in 2004 the South-Korean Government decided to guard its West- and East-Coast by cable based Tsunami detection stations. A prototype system was commissioned in November 2006 20 km South of Ulleong-Do island in the East Sea. Since then, the system continuously delivers data into the Korea Meteorological Administration (KMA) sensor network.
The increase on the demand for marine products and the decrease of the wild marine population has led to the culturing of several marine species. Within the molluscs the mussel is the second largest product by volume of marine aquaculture. Mussels are an ideal species for culture in the open ocean, referred to as offshore aquaculture. Several different systems are available for offshore mussel culture...
This paper describes the setting of the experiment for in situ measurements of breaking waves. The aim is to provide an insight in the wave breaking mechanism and the possible outcome is a statistical description of this mechanism which will be used together with airborne radar (SAR) data acquired on the same spot. It is well known that when the sea-state is high (3 to 4) the radar clutter is displaying...
The recent growing interest in underwater acoustic communication (UAC) requires an in depth understanding of a vast and diverse water medium. The UAC channel presents many difficulties such as high frequency, time, and space selectivity, frequency dependent noise, and significant range and band limitation on transmission. The traditional channel parameter measurement and estimation methods may not...
An iterative receiver scheme combining decision feedback equalizer (DFE) and bit interleaved coded modulation (BCIM-ID), suitable for transmission over frequency selective channels with large delay spread is proposed, where adaptive equalization and channel decoding are jointly optimized. Extensive simulation results presented for a realistic underwater time varying multipath channel exhibiting multipath...
On 31st January 2009, two numbers: ldquorange and bearingrdquo flashing up on a laptop screen, indicated that Autosub3 had returned from its last mission beneath the Pine Island Glacier (PIG) Ice Shelf in the Western Antarctic. The Autosub technical team from NOCS, Southampton, onboard the US ice breaker Nathanial B Palmer breathed a collective sigh of relief. Any significant technical failure would...
Today, due to the current state-of-the-art of embedded systems, underwater robotic vehicles are limited in both, their autonomy and capabilities. In order to increase their utility it is advantageous to run multiple vehicles at the same time whereby each vehicle serves as individual node in an underwater network. In this context a group of leading European vehicle manufacturers and researchers set...
Biological, oceanographic and geomorphologic data of the Azores were integrated into a Geographical Information System (GIS) in order to determine occurrence and spatial behavior of commercially-exploited coastal fishes in relation to benthic habitats. Essential fish habitats (EFHs) are identified and the information is incorporated into decision making tools to design a network of coastal Marine...
Conventional side scan sonars are generally single beam systems with a small horizontal and a large vertical beam width. The side scan sonar image of a scene is generated by stringing together the signals from successive pings. In contrast, Multi-Beam/Multi-Aspect side scan sonars create an image of a large scene with each single ping. Here, the fact is exploited that a transducer insonifies a horizontally...
We use an AUV, Starbug, to produce habitat maps by identifying benthos from their spectral signatures. This requires a measurement of the light attenuation in the water column at the current site. The study area usually contains two layers of water with distinct attenuation characteristics, which can vary substantially in response to events such as algal blooms and floods. Therefore it is necessary...
An autonomous underwater vehicle with a biomechanical propulsion system is a possible answer to the demand for small, silent sensor platforms in many fields. The design of Galatea, a bio-mimetic AUV, involves four aspects: hydrodynamic shape, the propulsion, the motion control systems and payload. The shape of the hull is based on a modified Wortmann FX 71-L-150/20 airfoil. Wind tunnel tests have...
In situ methane emission measurements from sediments are combined with water column backscatter anomalies recorded with an Acoustic Doppler Current Profiler (ADCP) integrated on a benthic observatory. During cruise SO191 to the Hikurangi Margin (New Zealand), the Fluid Flux Observatory (FLUFO) was deployed at a cold seep site at Omakere Ridge. The first 26 hours of in situ incubation revealed low...
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