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OCEANS '95. MTS/IEEE. Challenges of Our Changing Global Environment. Conference Proceedings.

9-12 Oct. 1995

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  • OCEANS '95 MTS/IEEE "Challenges of Our Changing Global Environment" Vol. 3

    Publication Year: 1995
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    Freely Available from IEEE
  • Authors index

    Publication Year: 1995
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    Freely Available from IEEE
  • Inverting tomographic data with neural nets

    Publication Year: 1995, Page(s):1501 - 1504 vol.3
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (351 KB)

    Ocean acoustic tomography is a synoptic observation method of the internal structure of the ocean. The underlying idea is to estimate the sound velocity environment (as well as temperature, salinity and currents) by inverting travels times issued from the propagation of sound between sources and receivers. Most of the inversion methods are deriving from a linearization around a prior reference sou... View full abstract»

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  • A Markov random field approach for restoration of underwater acoustic images

    Publication Year: 1995, Page(s):1900 - 1906 vol.3
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (633 KB)

    This paper describes a method for the restoration of underwater 3D acoustic images. Beamforming is used to build a 3D map associated with another image representing the confidence (i.e. reliability) of measures. Beamforming processes backscattered echoes (received by a two-dimensional array antenna) coming from a scene previously insonified, forming two images where each pixel represents the dista... View full abstract»

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  • Validation of satellite infrared radiometers and investigation of ocean-atmosphere interaction

    Publication Year: 1995, Page(s):2081 - 2085 vol.3
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (412 KB)

    A series of experiments to investigate ocean-atmosphere interaction will take place during July and August 1995 in Mutsu Bay, Honshu Island, Japan. This collaborative venture will utilise several instruments from both Japan and the UK with the objectives of investigating processes that define the signal measured by infrared radiometry during SST retrieval and validating various satellite radiomete... View full abstract»

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  • Characterization of a cylindrical vibrating body in shallow water from partial measurement of its radiated field

    Publication Year: 1995, Page(s):2076 - 2080 vol.3
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (288 KB)

    The retrieval of the normal velocity of a time-harmonic vibrating body placed in shallow water is attempted from values of the radiated field on a vertical array R of hydrophones. The body is a cylinder of closed convex cross-section (circular, elliptic). The vibration is not assumed symmetric. Data on R may be noisy and inaccuracy on the receiver locations may be introduced. A boundary integral f... View full abstract»

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  • Hybrid approach for accurate echo detection in the formation of acoustic images

    Publication Year: 1995, Page(s):1877 - 1882 vol.3
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (452 KB)

    This paper proposes a hybrid approach aimed at precise echo detection for improving short-range underwater images generated by beam-forming process. The final goal is the construction of the scene model as accurately as possible to be used by an autonomous vehicle to navigate in the environment. Our approach is essentially a voting method. It consists in the integration of two methods based on the... View full abstract»

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  • Global method for the validation of a double radiative transfer model. (Active and passive modes)

    Publication Year: 1995, Page(s):2071 - 2075 vol.3
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (340 KB)

    Proposes a method for the validation of atmospheric radiative transfer models. This method is aimed to be applied on a double model (using active and passive observations) developed at Louvain University (Belgium). It has been tested on a radiometric model for frequencies in the range 1 to 200 GHz and the results are shown View full abstract»

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  • A maximum entropy approach to filtering and reconstructive imaging of the underwater environment

    Publication Year: 1995, Page(s):1871 - 1876 vol.3
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (228 KB)

    In this paper an approximate autoregressive model is developed to image a combination of point targets and extended objects in the far field, from the returns collected by an array sonar. The method operates on a single snapshot, allowing for super-resolution imaging through application to non-stationary returns derived from multiple range cells. Furthermore, a novel adaptive spatial filter is des... View full abstract»

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  • Near-optimum detection of random signals of unknown location, structure, extent, and strength

    Publication Year: 1995, Page(s):1659 - 1664 vol.3
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (356 KB)

    A signal (if present) is located somewhere in a band of frequencies characterized by a total of N search bins. The signal occupies an arbitrary set of M of these bins, where not only is M unknown, but also, the locations of the particular M occupied bins are unknown. Also, the (common) signal strength per bin, S, is unknown. The detection performance of the v-th power-law device is determined and ... View full abstract»

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  • Concept of operations for the NAVOCEANO ORCA vehicle

    Publication Year: 1995, Page(s):1968 - 1975 vol.3
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (672 KB)

    The Naval Oceanographic Office (NAVOCEANO) plans to operate Oceanographic Remotely Controlled Automatons (ORCAs) as remotely operated vehicles aboard the new T-AGS 60 class survey ships. ORCA is an unmanned, diesel-powered semi-submersible vehicle outfitted with a shallow-water multibeam bathymetric system. Vehicle control and sensor data are telemetered between the vehicle and ship. Considerable ... View full abstract»

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  • Computer modelling of large, high-performance fiber rope properties

    Publication Year: 1995, Page(s):1563 - 1571 vol.3
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (660 KB)

    Rope development has historically involved building a prototype rope, testing it to determine performance, and then building another rope in an attempt to improve that performance. This empirical method was affordable with small conventional ropes. Interest is now focused on developing very large ropes made of polyester and high modulus materials such as aramid. For such ropes, the empirical metho... View full abstract»

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  • Design and test of a coding OFDM system on the shallow water acoustic channel

    Publication Year: 1995, Page(s):2065 - 2070 vol.3
    Cited by:  Papers (15)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (380 KB)

    In this paper, we present a multicarrier transmission system based on the OFDM principle using a guard interval and channel coding with interleaving. The shallow water acoustic channel is, on the one hand, frequency selective (presence of multiple paths), and on the other hand, non stationary (presence of Doppler effect). By introducing a guard interval, intersymbol interference due to channel sel... View full abstract»

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  • Object recognition by machine vision to enhance scene interpretation in an underwater application

    Publication Year: 1995, Page(s):1865 - 1870 vol.3
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (540 KB)

    Collaborative work is going on between University College London and Sira Ltd. to introduce artificial intelligence in the vision system for an underwater remotely operated vehicle (ROV). Onboard vision systems act as a close-range navigating tool for docking the vehicle onto a remote structure, as well as allowing close-range visual inspection. As the underwater environment produces poor quality ... View full abstract»

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  • Virtual world visualization for an autonomous underwater vehicle

    Publication Year: 1995, Page(s):1592 - 1600 vol.3
    Cited by:  Papers (11)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1100 KB)

    A critical bottleneck exists in autonomous underwater vehicle (AUV) design and development. It is tremendously difficult to observe, communicate with and test underwater robots, because they operate in a remote and hazardous environment where physical dynamics and sensing modalities are counterintuitive. An underwater virtual world can comprehensively model all necessary functional characteristics... View full abstract»

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  • AUV system requirements for coastal oceanography

    Publication Year: 1995, Page(s):1651 - 1658 vol.3
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (768 KB)

    Three classes of oceanographic AUVs addressing relevant distinct scientific and applied objectives in the Portuguese coastal waters are examined. Then, by assuming some mission organizations in the light of the current technological state-of-art, a set of functionalities required for an operational system are extracted. Finally, some requirements for the design and development of such a class of s... View full abstract»

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  • The first GPS based vessel traffic service system for an American inland waterway

    Publication Year: 1995, Page(s):2097 - 2103 vol.3
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (736 KB)

    The paper describes the design and the development of an advanced vessel traffic service system (VTS) that was demonstrated in 1994 on the section of the Saint Lawrence Seaway under control of the Saint Lawrence Seaway Development Corporation (SLSDC). Vessel traffic service on the Saint Lawrence Seaway has undergone little change since the Seaway opened in 1959. The current VTS system depends prim... View full abstract»

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  • Mixing in the wake of an aircraft carrier

    Publication Year: 1995, Page(s):1730 - 1744 vol.3
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1128 KB)

    A computational model, originally developed to study ship microbubble wakes, is to study the dispersal of shipboard discharge and possible resuspension of bottom sediment, in the near field of the wake of an aircraft carrier. The near field solution is then used to specify the initial condition for a second model which computes the far field particle dispersion and dilution due to ambient mixing e... View full abstract»

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  • Electronic nautical charting: role in sustainable development of marine transport operations

    Publication Year: 1995, Page(s):1955 - 1967 vol.3
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (580 KB)

    Electronic nautical charting plays a major role in providing safe and efficient navigation of vessels primarily involved in commerce, fishery landings, marine recreation, cruises and research activities on the civil side, and naval operations for the military. In order to determine the contributions of electronic charting to marine transport operations, and the priorities for converting to electro... View full abstract»

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  • Tension-tension fatigue test results for aramid and wire ropes

    Publication Year: 1995, Page(s):1557 - 1562 vol.3
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (204 KB)

    A great deal of interest and research has focused on the performance of high modulus fibers under tension-tension fatigue testing. Modeling and scaled-down testing helps us understand the modes of failure for ropes under cyclic loading. Whitehill Mfg. Corp. has done extensive in-house fatigue testing on aramid and wire ropes. Our results indicate that aramid rope is a fully viable option for many ... View full abstract»

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  • Induced dichroism excited atomic-line filter at 532.33 nm in potassium vapor for LIDAR

    Publication Year: 1995, Page(s):2061 - 2064 vol.3
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (288 KB)

    A narrow band optical filter with 40% transmission and 0.01 nm bandwidth has been demonstrated at 532 nm. The filter uses potassium vapor as an active medium pumped by a circularly polarized beam. Theoretical and experimental aspects of this atomic filter are discussed View full abstract»

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  • Image quality improvement of underwater synthetic aperture ultrasonic holography by deconvolution of spatial response of transducers

    Publication Year: 1995, Page(s):1859 - 1864 vol.3
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (396 KB)

    This paper studies the effect of transducer spatial response on the measured underwater ultrasonic pressure field, and eliminates this effect by using of the deconvolution technique to improve the image resolution and modulation transfer function (MTF) of underwater synthetic aperture ultrasonic holography (SAUH) imaging systems, in which resolution is usually limited by the spatial size of transd... View full abstract»

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  • Optimization of under-constrained control effector allocations

    Publication Year: 1995, Page(s):1446 - 1453 vol.3
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (408 KB)

    An alternative method for dealing with the travel limitations of control surfaces arranged in an X-configuration on underwater vehicles is presented. The X-configuration uses four effectors to implement three functions: roll, pitch, and yaw moment generation. Each effector saturates due to stall at some angle of attack. As a result, the desired set of roll, pitch and yaw moments may not be achieva... View full abstract»

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  • Image resolution improvement of underwater synthetic aperture ultrasonic holography by virtual aperture augmentation technique

    Publication Year: 1995, Page(s):1671 - 1675 vol.3
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (288 KB)

    This paper studies the image resolution improvement technique for the underwater synthetic aperture ultrasonic holographic (SAUH) imaging system in which the aperture size is limited For conventional SAUH imaging systems, the better image resolution call be improved by increasing the aperture size at the expense of aperture distortion and the scanning time. In this paper, we propose an algorithm t... View full abstract»

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  • Processing, presentation, and data basing of acoustic imagery

    Publication Year: 1995, Page(s):1582 - 1591 vol.3
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1572 KB)

    The Naval Oceanographic Office (NAVOCEANO) collects and processes acoustic imagery from multiple sensors at various frequencies. These currently include the towed 12-kHz SEAMAP system, the towed 100-kHz hydrographic sidescan, and the hull-mounted multibeam bathymetric sonars. The hull-mounted systems at NAVOCEANO providing acoustic imagery include the 12-kHz Sonar Array Survey System (SASS) and co... View full abstract»

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