OCEANS 2007最新文献

{"title":"The SSBL Positioning for The AUV with Data Transmission","authors":"Y. Watanabe, H. Ochi, T. Shimura","doi":"10.1109/OCEANS.2007.4449216","DOIUrl":"https://doi.org/10.1109/OCEANS.2007.4449216","url":null,"abstract":"The super short base line (SSBL) method of the acoustic underwater positioning is commonly used due to the simplicity to operation. Though the accuracy of each single shot positioning is not so high. The SSBL for the autonomous underwater vehicle (AUV) becomes more accurate and helpful to navigate the AUV by transmitting the data obtained in each side of seabed and surface. The usefulness of this approach is shown. The method of the data transmission with the acoustic positioning pulse is considered especially for the problem of inter-symbol interference (ISI). The experiments of the data transmission are performed. The experiments are applied the direct sequence spread spectrum (DSSS) and the results of two patterns that are success and failure examples are shown.","PeriodicalId":214543,"journal":{"name":"OCEANS 2007","volume":"91 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125853597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Forensic Techniques for Investigating the Causes of Fiber Rope Failures","authors":"J. Nichols, S. Banfield, J. Flory","doi":"10.1109/OCEANS.2007.4449341","DOIUrl":"https://doi.org/10.1109/OCEANS.2007.4449341","url":null,"abstract":"This paper discusses techniques that are used to determine the underlying causes of fiber rope failures. Rope failures can exhibit a complex mixture of features that are sometimes difficult to interpret and understand. It is necessary to distinguish between those features which occurred during or after a failure from those that may have caused or contributed to it and this requires both judgement and experience. An investigation always starts with a visual examination and preliminary unravelling of the fail zones of the rope. Selective tensile testing is then used to generate data that can be used to estimate the rope strength at the time of fail. If necessary, further techniques such as optical and scanning electron microscopy are used to provide additional information for a more detailed understanding of a failure. Thermal stability and UV resistance may also have to be assessed when investigating failures of certain types of rope and techniques for doing these investigations are also described. As with any type of forensic investigation, the objective must be to gather as much information as possible, from as many different perspectives as possible, to permit the correct conclusion to be drawn as to the cause or causes of any rope failure. Examples from several fiber rope failure investigations are discussed in the paper.","PeriodicalId":214543,"journal":{"name":"OCEANS 2007","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125859077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"More Than One-Way to Catch a Fish: Use of Effective Translation of Ocean Science to Promote Ocean Literacy","authors":"B. Meeson, J. McDonnell, C. Parsons","doi":"10.1109/OCEANS.2007.4449347","DOIUrl":"https://doi.org/10.1109/OCEANS.2007.4449347","url":null,"abstract":"An understanding and appreciation of the ocean, Great Lakes and coasts' role in our lives (from commerce to recreation to weather) and our interdependence upon them is a chief goal of the ocean literacy initiative. Today most Americans undervalue the ocean because few know and value the vital functions the ocean performs in service to our society and to each of us individually. One requisite for ocean literacy is the promotion of effective life-long learning of these vital functions and services through sustained communication that captures both our hearts and minds. Story development and data translation address one aspect of lifelong learning, the sustained supply of compelling and accurate science and technology stories about the ocean, coasts, and Great Lakes. Stories that educators and communication professionals can incorporate into all types of learning materials. Here we continue our examination of two models (Government Research Enterprise and an Academic Research Organization) that are case studies in developing and identifying highly effective story development and data translation practices.","PeriodicalId":214543,"journal":{"name":"OCEANS 2007","volume":"41 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125881033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Array Modeling of Active Sonar Clutter","authors":"D. Abraham","doi":"10.1109/OCEANS.2007.4449244","DOIUrl":"https://doi.org/10.1109/OCEANS.2007.4449244","url":null,"abstract":"Active sonar systems operating in shallow water environments often deal with excessive false alarms, generically referred to as clutter, that are more numerous than expected for Rayleigh distributed reverberation. It is known that the clutter probability density function, and therefore the probability of false alarm (Pfalpha), depends on the scattering sources, propagation conditions, sonar system and signal processing. In this paper the effect of sonar array processing on clutter statistics is evaluated through approximation by the K distribution where the shape parameter (alpha tilde) provides an inverse relationship to Pfalpha with decreases in alpha tilde representing an increase in Pfalpha. When the transmit waveform bandwidth is narrowband with respect to the array processing and propagation is restricted to the direct path, a was found to be separable into the product of an array-processing effect, a transmit-waveform effect, and a clutter-source scattering effect. The array effect was found to coarsely follow the array beamwidth, although precise evaluation is straightforward given the array beampattern and, for an equi-spaced line array, an asymptotic approximation was seen to be quite accurate for even moderate array sizes. As might be expected, array design or processing that tends to increase the beamwidth (e.g., reducing the size of an array or transmit waveform frequency, steering away from broadside to a line array, or shading an array to reduce sidelobes) was found to increase alpha tilde. Uniform shading was found to provide a practical, though not exact, lower bound on alpha tilde for common array shading functions.","PeriodicalId":214543,"journal":{"name":"OCEANS 2007","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126061020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"T7 - End User Application of Underwater Cable and Connectors","authors":"Brock Rosenthal, K. Hardy, C. Peters, Andrew Gardner","doi":"10.1109/OCEANS.2007.4449450","DOIUrl":"https://doi.org/10.1109/OCEANS.2007.4449450","url":null,"abstract":"UhdowtWauz ca1bles cdhd connectors ptoVide sytem flbkblijty,CS dO6 service, dh tfhb desig cidVdhtdoesfbt 0hndbtsd equipm (D t. Th is oneboy Shbt bourse Will hb1p ondAisors identify Cdh pri6titi2e critical dlecisions thdct Will load1 tb fh8e b6st connector dhd dbld system The fhdit d6fihod dooitdCtibh. Lbddez in undbrvdfte cdblesg connedf6tO dhd f Stihd Wi II roeS hf str idhff6 Wdrd fuill dCy~session tb hbl1p bboth bhdAAese and m0hufctUetors dthieve suctbt8 by soedklho the some ldndLjdg6. Attendees lbdVO With d Wbrking khmki1dde dhd dbility tb soocify LjhtdeStor tdblb and connectors fbr thbit harsh Onvironmht dpoiictitibite lbdthing ff6m experiences ih thb fdbtbry dnd fiid. Course notes will bO provided dhd tbchAnicdl reference r-ndeNdl vvill b5e prvidled tb dil dtthdees on CD.","PeriodicalId":214543,"journal":{"name":"OCEANS 2007","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126137293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phase Space Approach and Approximations for Wave Propagation","authors":"Leon Cohen, P. Loughlin","doi":"10.1109/OCEANS.2007.4449249","DOIUrl":"https://doi.org/10.1109/OCEANS.2007.4449249","url":null,"abstract":"We consider wave propagation in a dispersive medium with damping. We have previously shown that a significant simplification occurs if one formulates the wave propagation problem in phase space. In our previous work, we used the Wigner distribution as the phase space representation. In this paper, we extend this approach to other phase space distributions, including the well-known spectrogram (or lofargram), and also to the ambiguity function.","PeriodicalId":214543,"journal":{"name":"OCEANS 2007","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126782548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tsunami Detection Systems for International Requirements","authors":"R. Lawson","doi":"10.1109/OCEANS.2007.4449208","DOIUrl":"https://doi.org/10.1109/OCEANS.2007.4449208","url":null,"abstract":"Results are presented regarding the first commercially available, fully operational, tsunami detection system to have passed stringent U.S. government testing requirements and to have successfully demonstrated its ability to detect an actual tsunami at sea. Spurred by the devastation of the December 26, 2004, Indian Ocean tsunami that killed more than 230,000 people, the private sector actively supported the Intergovernmental Oceanographic Commission's (IOC's) efforts to develop a tsunami warning system and mitigation plan for the Indian Ocean region. As each country in the region developed its requirements, SAIC recognized that many of these underdeveloped countries would need significant technical assistance to fully execute their plans. With the original focus on data fusion, consequence assessment tools, and warning center architecture, it was quickly realized that the cornerstone of any tsunami warning system would be reliable tsunami detection buoys that could meet very stringent operational standards. Our goal was to leverage extensive experience in underwater surveillance and oceanographic sensing to produce an enhanced and reliable deep water sensor that could meet emerging international requirements. Like the NOAA Deep-ocean Assessment and Recording of Tsunamis (DARTtrade) buoy, the SAIC Tsunami Buoy (STB) system consists of three subsystems: a surface communications buoy subsystem, a bottom pressure recorder subsystem, and a buoy mooring subsystem. With the operational success that DART has demonstrated, SAIC decided to build and test to the same high standards. The tsunami detection buoy system measures small changes in the depth of the deep ocean caused by tsunami waves as they propagate past the sensor. This is accomplished by using an extremely sensitive bottom pressure sensor/recorder to measure very small changes in pressure as the waves move past the buoy system. The bottom pressure recorder component includes a processor with algorithms that recognize these characteristics, and then immediately alerts a tsunami warning center through the communications buoy when the processor senses one of these waves. In addition to the tsunami detection buoy system, an end-to-end tsunami warning system was developed that builds upon the country's existing disaster warning infrastructure. This warning system includes 1) components that receive, process, and analyze buoy, seismic and tide gauge data; 2) predictive tools and a consequence assessment tool set to provide decision support; 3) operation center design and implementation; and 4) tsunami buoy operations and maintenance support. The first buoy was deployed Oct. 25, 2006, approximately 200 nautical miles west of San Diego in 3,800 meters of water. Just three weeks later, it was put to the test during an actual tsunami event. On Nov. 15, 2006, an 8.3 magnitude earthquake rocked the Kuril Islands, located between Japan and the Kamchatka Peninsula of Russia. That quake generated a small tsu","PeriodicalId":214543,"journal":{"name":"OCEANS 2007","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116417601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimates of Radial Current Error from High Frequency Radar using MUSIC for Bearing Determination","authors":"T. Cook, T. DePaolo, E. Terrill","doi":"10.1109/OCEANS.2007.4449257","DOIUrl":"https://doi.org/10.1109/OCEANS.2007.4449257","url":null,"abstract":"Quality control of surface current measurements from high frequency (HF) radar requires understanding of individual error sources and their contribution to the total error. Radial velocity error due to uncertainty of the bearing determination technique employed by HF radar is observed with both direction finding and phased array techniques. Surface current estimates utilizing Multiple Signal Classification (MUSIC) direction finding algorithm with a compact antenna design are particularly sensitive to the radiation pattern of the receive and transmit antennas. Measuring the antenna pattern is a common and straightforward task that is essential for accurate surface current measurements. Radial current error due to the a distorted antenna pattern is investigated by applying MUSIC to simulated HF radar backscatter for an idealized ocean surface current. A Monte Carlo type treatment of distorted antenna patterns is used to provide statistics of the differences between simulated and estimated surface current. RMS differences between the simulated currents and currents estimated using distorted antenna patterns are 3-12 cm/s greater than those using perfect antenna patterns given a simulated uniform current of 50 cm/s. This type of analysis can be used in conjunction with antenna modeling software to evaluate possible error due to the antenna patterns before installing a HF radar site.","PeriodicalId":214543,"journal":{"name":"OCEANS 2007","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122296928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Autonomous Boat Based Synthetic Aperture Sonar","authors":"S. Silva, S. Cunha, A. Matos, N. Cruz","doi":"10.1109/OCEANS.2007.4449358","DOIUrl":"https://doi.org/10.1109/OCEANS.2007.4449358","url":null,"abstract":"This paper describes a Synthetic Aperture Sonar (SAS) system being developed at the University of Porto to be used in a small autonomous boat for the survey of shallow water environments, such as rivers, deltas, estuaries and dams. Its purpose is to obtain high resolution echo reflectivity maps through synthetic aperture techniques, taking advantage of the high precision navigation system of the boat. In the future the production of bottom tomography maps is also considered through the use of interferometric imaging techniques.","PeriodicalId":214543,"journal":{"name":"OCEANS 2007","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122324917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of Spilled Oil Tracking Autonomous Buoy System","authors":"H. Senga, N. Kato, Asuka Ito, Hiroki Niou, M. Yoshie, I. Fujita, Kazuyuki Igarashi, Etsuro Okuyama","doi":"10.1109/OCEANS.2007.4449148","DOIUrl":"https://doi.org/10.1109/OCEANS.2007.4449148","url":null,"abstract":"Spilled oil from stranded ship damages not only the ocean environment but also the regional economics. In order to prevent such damages from expanding, we are developing a system using autonomous buoys. When the oil spill accident happens, several buoys are dropped into the sea. While the buoys drift along with spilled oil, those send some useful data such as its location, the meteorological and oceanographic data around them, in real time. According to the effect of wind driven water currents on the free surface, the buoys tend to drift apart from spilled oil. Therefore, the buoys must have the function of detecting and tracking spilled oil. In this paper, the concept of the buoy system and the mechanism of tracking spilled oil are firstly introduced. Then, the sensors to detect spilled oil are described. Next, the numerical scheme is explained to design the buoy and verify its maneuverability. Some experiments using a buoy model were carried out to verify the maneuverability and tracking ability of this buoy. These results show that the buoy could track the target by using the developed tracking algorithm.","PeriodicalId":214543,"journal":{"name":"OCEANS 2007","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122547190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}