By Topic

OCEANS '94. 'Oceans Engineering for Today's Technology and Tomorrow's Preservation.' Proceedings

Date 13-16 Sep 1994

Go

Filter Results

Displaying Results 1 - 25 of 110
  • Oceanographic data collection system

    Publication Year: 1994, Page(s):III/51 - III/62 vol.3
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (700 KB)

    The study and surveillance of the oceans more and more extensively requires the use of space-dedicated resources for the collection of data resulting from the measurements made in situ by beacons. The limitations of the ARGOS system used by SHOM (French Navy Hydrographic and Oceanographic Department) to this effect have shown this tool not to be optimally suited to the newly emerging needs. This i... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The NELS network: (Northwest European Loran C System)

    Publication Year: 1994, Page(s):III/551 - III/558 vol.3
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (336 KB)

    A large number of people know of the GPS (Global Positioning System). The GPS is entirely under the authority of the American military. At any time, non-aware users can be misled about their real positions. This is the reason why it is advisable not to have a complete reliance on the GPS system. Thus, a second system of navigation assistance is available in many areas of the Northern Hemisphere: L... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Development of a dynamic simulator for stability anal control of towed underwater vehicles

    Publication Year: 1994, Page(s):III/431 - III/436 vol.3
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (392 KB)

    The paper presents the derivation of a mathematical model and a simulation code for the analysis of stability and control characteristics of towed underwater vehicles. The main objectives of the work were to develop an accurate, easy-to-use software, to be used in the analysis of dynamic behavior as well as in the synthesis of guidance and control strategies. The program has been written entirely ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • United States Navy operational oceanographic nowcast/forecast system

    Publication Year: 1994, Page(s):III/45 - III/50 vol.3
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (564 KB)

    The Commander, Naval Meteorology and Oceanography Command operates a system of meteorological and oceanographic models for continuous, realtime nowcast/forecast support to United States Department of Defense forces, particularly for Navy/Marine Corps safety of navigation, exploitation of oceanic fronts, and nearshore tactical employment of ships, aircraft and personnel for mine warfare, strike war... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Precision attitude measurements for survey vessels

    Publication Year: 1994, Page(s):III/545 - III/550 vol.3
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (344 KB)

    Accurate measurement of a vessel's attitude angles is necessary for certain types of instrumentation, in particular multibeam echo sounders and underwater positioning of the supershort baseline type. While inertial navigation platforms have the required accuracy, the cost of such units is prohibitively high for the majority of users. The authors investigate a different approach which may be more c... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Hydroacoustical experiments for determination of sediment parameters

    Publication Year: 1994, Page(s):III/207 - III/212 vol.3
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (476 KB)

    Three different kinds of hydroacoustical experiments conducted in Kalmarsund in the Baltic are described: (1) excitation with a slowly moving monofrequency source for transmission loss measurements and modal structure analysis, (2) excitation of transient waves using explosive charges, (3) excitation with a frequency sweep for analysis of transmission loss as function of frequency. The experiments... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Structure of operational oceanographic nowcast and forecast systems

    Publication Year: 1994, Page(s):III/88 - III/92 vol.3
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (284 KB)

    Presents in a pedagogical manner some elements leading to operational nowcast and forecast oceanic systems serving navies View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Hydrodynamic manoeuvrability data of a flatfish type AUV

    Publication Year: 1994, Page(s):III/425 - III/430 vol.3
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (452 KB)

    Hydrodynamic manoeuvrability data of the flatfish type autonomous underwater vehicle (AUV) “MARIUS” are presented. “MARIUS” was developed under the EC MAST Programme as a vehicle for seabed inspection and environmental surveys in coastal waters. The AUV has an overall length of 4.5 m and is driven by two propellers and four thrusters. The data comprise added mass and inerti... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Multiple agents architecture for intelligent command and control system of AUVs : application to the MARIUS vehicle

    Publication Year: 1994, Page(s):III/126 - III/131 vol.3
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (504 KB)

    This paper addresses the problem of intelligent command and control systems for AUVs. It presents a conceptual multiple agents based architecture proposed for the MARIUS prototype vehicle (devoted to coastal survey missions). The paper presents the characteristics of the vehicle system and a synthesis of the functional requirements to be fulfilled; it describes the proposed multiagents architectur... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Multifrequency acoustic imaging of suspended sediment processes

    Publication Year: 1994, Page(s):III/263 - III/268 vol.3
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (516 KB)

    Multifrequency acoustic backscattering has been used to obtain images of suspended sediments. A number of results are presented which show how the technology can be used to examine the broad picture on a tidal scale, or focus on detailed particular events which only last a period of seconds View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Simultaneous use of eulerian and lagrangian currents measured by VHF radars for estimating the horizontal diffusion coefficient in coastal circulation

    Publication Year: 1994, Page(s):III/40 - III/44 vol.3
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (328 KB)

    A VHF radar has been used to locate a drifting transponder for measuring the lagrangian circulation in the coastal zone. It is expected that simultaneous use of several drifters will give an insight into small scale dispersion and diffusion phenomena. The paper describes the radar and transponder system, and outlines the method used to estimate the horizontal diffusion coefficient View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Electronic navigational chart data

    Publication Year: 1994, Page(s):III/541 - III/544 vol.3
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (396 KB)

    As in other hydrographic offices, SHOM (Service Hydrographique et Oceanographique de la Marine) is developing databases for electronic chart display and information systems (ECDIS). Those databases are populated by information coming from thematic files or by digitization of paper charts. Selection of information needed for ECDIS is dictated by specifications defined by the International Hydrograp... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Measurement of sea bed topography and bistatic scattering coefficients with steered frequency source arrays

    Publication Year: 1994, Page(s):III/200 - III/206 vol.3
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (404 KB)

    A method of measuring bottom topography and bistatic scattering coefficients with steered frequency source (SFS) arrays is described and illustrated with modeled reverberation data. SFS array design principles are summarized and methods of analyzing the data to obtain sea bed topography and bistatic scattering coefficients are outlined. The SFS source radiates acoustic energy in a set of narrow ve... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Marine geophysics modeling with geographic information systems

    Publication Year: 1994, Page(s):III/528 - III/531 vol.3
    Cited by:  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (248 KB)

    Geographic information systems (GIS) are ideal tools for the display and analysis of georeferenced data. What is not so well appreciated is that a GIS can serve as a software/data management system that integrates software (in-house and third-party) with data (in a variety of formats) to form a unified display/analysis tool. Analysts can continue to use the software with which they are familiar, w... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • New advanced underwater navigation techniques based on surface relay buoys

    Publication Year: 1994, Page(s):III/395 - III/402 vol.3
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (472 KB)

    The development of medium and long range UUVs, associated with most recent operational concepts create new requirements for advanced underwater navigation systems that must be accurate, easy to deploy at sea and low cost. At the same time, the broad use of GPS for navigation purposes allows manufacturers to produce low cost and highly accurate receivers, opening the market to new solutions in unde... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • SWAFS: shallow water analysis and forecast system

    Publication Year: 1994, Page(s):III/82 - III/87 vol.3
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (464 KB)

    A numerical ocean forecast system has been assembled and applied to several semi-enclosed basins. The modelling system includes a numerical model of ocean circulation, a data assimilation scheme, real-time meteorological forecasts, and data bases of in situ temperature observations and sea-surface temperatures inferred from satellites. Forecast results for the Red Sea are shown View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Dynamic properties of AUV “Typhlonus”

    Publication Year: 1994, Page(s):III/421 - III/424 vol.3
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (220 KB)

    In the paper the questions of choice of Typhlonus autonomous underwater vehicle (AUV) hydrodynamic properties and features of the motion control system by velocity, depth and heading channels, are considered. The evaluation of vehicle dynamic properties is given, using sea tests results. The vehicle main properties, minimal hydrodynamic resistance and high maneuverability with stability, provides ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Real time underwater communications

    Publication Year: 1994, Page(s):III/501 - III/506 vol.3
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (308 KB)

    Achieving reliable high speed digital communications over an underwater channel is a challenge that many scientists are trying to take up. For various applications such as remote control and data exchange, for example between an autonomous underwater vehicle and a surface vessel, the need is getting more and more important in designing reliable communications systems by means of acoustic waves. Th... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A drifter for tracking oil spills using the Argos system

    Publication Year: 1994, Page(s):III/292 - III/297 vol.3
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (404 KB)

    Several versions of oil spill markers have been developed to assist in the tracking of spills in the coastal waters of western Canada. The authors fitted the markers with a fabric skirt to slow their descent from aircraft and found that the skirt helped simulate the movement of an oil spill if it remained attached to the marker. The first operational version of these spill markers, incorporating a... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Depth control of an unmanned underwater vehicle using neural networks

    Publication Year: 1994, Page(s):III/121 - III/125 vol.3
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (292 KB)

    Artificial neural networks offer an alternative strategy for the non-linear control of unmanned underwater vehicles (UUVs). This paper presents the results of a simulation study into the development of a neural network controller for depth control of a UUV. Results presented compare the performance of the neural controller based on the multilayered perceptron (MLP) chemotaxis training algorithm wi... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Analysis of the performance of an underwater acoustic communications system and comparison with a stochastic model

    Publication Year: 1994, Page(s):III/478 - III/482 vol.3
    Cited by:  Papers (11)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (412 KB)

    This paper describes the testing of an experimental 50 kHz DPSK acoustic data telemetry system developed at The University of Birmingham. The experiment was conducted across the Solent, at Southampton in the United Kingdom. The Solent is a extremely shallow channel with a severe multipath and high shipping noise. Excellent performance was obtained under favourable transmission conditions. The perf... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Measurements with a three frequency echo sounder for the detection of suspended matter in a river estuary

    Publication Year: 1994, Page(s):III/258 - III/262 vol.3
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (268 KB)

    Field measurements of backscattered acoustic energy taken with a three frequency echo sounder in an estuary under tidal influences are presented. The vertical and temporal distribution of suspended matter, as well as settling and resuspension effects are analysed and discussed View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Lagrangian ambient noise drifter

    Publication Year: 1994, Page(s):III/34 - III/39 vol.3
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (420 KB)

    The Defence Research Establishment Atlantic has carried out an experiment to study the relationship between ambient noise and oceanographic features in regions of pronounced oceanic currents, such as the Gulf Stream or its eddies, using a field of purpose built, long life drifting buoys developed and maintained at sea by Seimac Limited, of Dartmouth, Canada. These Lagrangian Ambient Noise Drifters... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Deep scattering layer investigation through multi-beam bathymetry

    Publication Year: 1994, Page(s):III/184 - III/188 vol.3
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (260 KB)

    It has been suggested that perhaps a multi-beam sonar would be a useful tool for studying the reverberation contours of the biologically active plankton regions of the ocean known as the deep scattering layer, DSL. A brief experiment, utilizing the SASS multi-beam sonar on board the US Navy's oceanographic survey ship USNS Tanner during sea trials in December 1992, was performed to evaluate this p... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Turbine under Gulf Stream (TUGS) overview of an energy source potential

    Publication Year: 1994, Page(s):III/443 - III/448 vol.3
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (488 KB)

    The authors present the details of a turbine under the Gulf Stream (TUGS) proposal submitted to the Advance Research Projects Agency (ARPA) under the Technology Reinvestment Project (TRP). The project is to design, build, and deploy the prototypes necessary to demonstrate the economic and technical feasibility of generating electric power from the Gulf Stream. The project is based in part on new g... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.