Pub Date : 2008-09-01DOI: 10.1109/OCEANS.2008.5151840
W. Gu, Jianhua Wang, Jianxin Chu, Xixia Huang
In this paper, a wireless data transmission system used in unmanned surface vehicles is presented. To improve reliability, wireless local network based on IP is employed. Through interface protocol, multi-modal data from different observation instruments or equipments are converted into the uniform specification suitable for transmission. Different control methods of data transmission are discussed. Experiment results from a unmanned surface vehicle sailing in the Yangtze River estuary show that the wireless data transmission system is suitable for applicable use.
{"title":"Study on wireless data transmission of an autonomous water vehicle for ocean observation","authors":"W. Gu, Jianhua Wang, Jianxin Chu, Xixia Huang","doi":"10.1109/OCEANS.2008.5151840","DOIUrl":"https://doi.org/10.1109/OCEANS.2008.5151840","url":null,"abstract":"In this paper, a wireless data transmission system used in unmanned surface vehicles is presented. To improve reliability, wireless local network based on IP is employed. Through interface protocol, multi-modal data from different observation instruments or equipments are converted into the uniform specification suitable for transmission. Different control methods of data transmission are discussed. Experiment results from a unmanned surface vehicle sailing in the Yangtze River estuary show that the wireless data transmission system is suitable for applicable use.","PeriodicalId":113677,"journal":{"name":"OCEANS 2008","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133094457","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}
Pub Date : 2008-09-01DOI: 10.1109/OCEANS.2008.5151842
Liu Jing-biao, Cai Wen-yu
Deep-sea visual exploration system plays an important role in the area of deep-sea expedition. Because of the harsh ocean environment, the deep-sea visual exploration system may face many problems such as high press of deep sea, instantaneous impact, deep-sea surge, local high temperature etc. Therefore, most current deep-sea visual exploration systems are not practicable. In this paper, considering the strongpoint of MPEG-4 coding and decoding technology with G.SHDSL modulation and demodulation technology, we designed a deep-sea visual exploration device based on 10000 m coaxial cable and MPEG-4 video server. Moreover, as a step up, computer vision based on OpenCV development kit has been introduced in this deep-sea visual exploration device. As a scientific discipline, computer vision is concerned with the theory for building artificial systems that obtain information from images, on the other hand, computer vision technology studies and describes artificial vision system that is implemented in software and/or hardware. With computer vision technology, deep-sea visual exploration system can obtain better performance and is intelligent enough to deal with some simply instance. As a consequence, the proposed deep-sea visual exploration device has been working on the ship named as ocean-one for many years, and has obtained many wonderful deep-sea video material, as a result, has made important contributions to ocean investigation enterprise of China.
{"title":"OpenCV based computer vision of deep-sea visual exploration system","authors":"Liu Jing-biao, Cai Wen-yu","doi":"10.1109/OCEANS.2008.5151842","DOIUrl":"https://doi.org/10.1109/OCEANS.2008.5151842","url":null,"abstract":"Deep-sea visual exploration system plays an important role in the area of deep-sea expedition. Because of the harsh ocean environment, the deep-sea visual exploration system may face many problems such as high press of deep sea, instantaneous impact, deep-sea surge, local high temperature etc. Therefore, most current deep-sea visual exploration systems are not practicable. In this paper, considering the strongpoint of MPEG-4 coding and decoding technology with G.SHDSL modulation and demodulation technology, we designed a deep-sea visual exploration device based on 10000 m coaxial cable and MPEG-4 video server. Moreover, as a step up, computer vision based on OpenCV development kit has been introduced in this deep-sea visual exploration device. As a scientific discipline, computer vision is concerned with the theory for building artificial systems that obtain information from images, on the other hand, computer vision technology studies and describes artificial vision system that is implemented in software and/or hardware. With computer vision technology, deep-sea visual exploration system can obtain better performance and is intelligent enough to deal with some simply instance. As a consequence, the proposed deep-sea visual exploration device has been working on the ship named as ocean-one for many years, and has obtained many wonderful deep-sea video material, as a result, has made important contributions to ocean investigation enterprise of China.","PeriodicalId":113677,"journal":{"name":"OCEANS 2008","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134311709","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}
Pub Date : 2008-09-01DOI: 10.1109/OCEANS.2008.5152022
J. Morris, V. Osychny, A. Turner
Leeway, defined as the movement of the search object through water caused by the action of wind on the exposed surfaces of the object, is fundamental to search planning. Over the past several years, the U.S. Coast Guard (USCG) Research and Development Center (R&DC) and the Canadian Coast Guard (CCG) have participated in leeway studies of various drift targets such as life rafts, evacuation vessels, sailboats, and other targets of interest. The leeway coefficients computed for each drift target generated from these leeway studies will be used in the new USCG Search and Rescue (SAR) planning software, the Search and Rescue Optimal Planning System (SAROPS), to define potential search areas during SAR operations. In the fall of 2005, the R&DC conducted leeway testing of two specific drift objects on behalf of the U.S. Naval Submarine Medical Research Laboratory: the Mark-10 Submarine Escape and Immersion Equipment (SEIE) life raft, and the Submarine Emergency Position Indicating Radio Beacon (SEPIRB). These studies were performed off the coast of St. John's, Newfoundland, Canada where open ocean conditions can be obtained within several miles from shore. Multiple drift runs were completed for each type of object to evaluate their behavior in response to various wind and sea conditions, producing object drift data under a wide variety of conditions. During the course of the study, each target was tracked by an on-board GPS receiver and data logger to yield high-resolution speed and direction over ground data. Wind velocity and sea conditions were measured by meteorological and wave rider buoys deployed within the study area to characterize environmental forcing conditions. The leeway of one SEIE raft was measured directly by a 1200 kHz acoustic Doppler current profiler (ADCP) gimbal-mounted and in a down-looking orientation, as well as multiple Self Locating Datum Marker Buoys (SLDMBs) that reported their respective positions via satellite at 30-minute intervals. Leeway of the remaining objects was determined indirectly by subtracting the surface current vector of adjacent SLDMBs from the drift object vector motion recorded by its onboard GPS receiver. Because all search objects were in the vicinity of the SLDMB field, a comparison between the direct and indirect leeway motion could be made for the ADCP-equipped SEIE raft. This value was then correlated to recorded wind speed and direction, and subjected to error analysis and statistical validation. This paper focuses on the methodology employed during the field study and provides a detailed description of the post-processing routines used to derive leeway coefficients for the SEIE for U.S. Navy search planning, and for use by the USCG in its SAROPS planning software. Estimates of the surface current for each drift target to support indirect leeway calculations relied on a statistical interpolation technique and consisted of steps described in the paper below. The resulting time series constituted a d
{"title":"Analytical techniques for the calculation of leeway as a basis for search and rescue planning","authors":"J. Morris, V. Osychny, A. Turner","doi":"10.1109/OCEANS.2008.5152022","DOIUrl":"https://doi.org/10.1109/OCEANS.2008.5152022","url":null,"abstract":"Leeway, defined as the movement of the search object through water caused by the action of wind on the exposed surfaces of the object, is fundamental to search planning. Over the past several years, the U.S. Coast Guard (USCG) Research and Development Center (R&DC) and the Canadian Coast Guard (CCG) have participated in leeway studies of various drift targets such as life rafts, evacuation vessels, sailboats, and other targets of interest. The leeway coefficients computed for each drift target generated from these leeway studies will be used in the new USCG Search and Rescue (SAR) planning software, the Search and Rescue Optimal Planning System (SAROPS), to define potential search areas during SAR operations. In the fall of 2005, the R&DC conducted leeway testing of two specific drift objects on behalf of the U.S. Naval Submarine Medical Research Laboratory: the Mark-10 Submarine Escape and Immersion Equipment (SEIE) life raft, and the Submarine Emergency Position Indicating Radio Beacon (SEPIRB). These studies were performed off the coast of St. John's, Newfoundland, Canada where open ocean conditions can be obtained within several miles from shore. Multiple drift runs were completed for each type of object to evaluate their behavior in response to various wind and sea conditions, producing object drift data under a wide variety of conditions. During the course of the study, each target was tracked by an on-board GPS receiver and data logger to yield high-resolution speed and direction over ground data. Wind velocity and sea conditions were measured by meteorological and wave rider buoys deployed within the study area to characterize environmental forcing conditions. The leeway of one SEIE raft was measured directly by a 1200 kHz acoustic Doppler current profiler (ADCP) gimbal-mounted and in a down-looking orientation, as well as multiple Self Locating Datum Marker Buoys (SLDMBs) that reported their respective positions via satellite at 30-minute intervals. Leeway of the remaining objects was determined indirectly by subtracting the surface current vector of adjacent SLDMBs from the drift object vector motion recorded by its onboard GPS receiver. Because all search objects were in the vicinity of the SLDMB field, a comparison between the direct and indirect leeway motion could be made for the ADCP-equipped SEIE raft. This value was then correlated to recorded wind speed and direction, and subjected to error analysis and statistical validation. This paper focuses on the methodology employed during the field study and provides a detailed description of the post-processing routines used to derive leeway coefficients for the SEIE for U.S. Navy search planning, and for use by the USCG in its SAROPS planning software. Estimates of the surface current for each drift target to support indirect leeway calculations relied on a statistical interpolation technique and consisted of steps described in the paper below. The resulting time series constituted a d","PeriodicalId":113677,"journal":{"name":"OCEANS 2008","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133840478","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}
Pub Date : 2008-09-01DOI: 10.1109/OCEANS.2008.5152020
M. Slater, J. Snyder
The international emphasis on climate change has prompted numerous initiatives in ocean observation. These initiatives require the widespread use of undersea networks for scientific research. The resulting demand for reliable sub-sea networks installed in a variety of environments poses dramatic design challenges. Designers draw solutions from academic networks such as MARS and VENUS, commercial networks linking oil platforms, and military surveillance systems or undersea ranges. To meet user requirements and answer the technical challenges, system implementers must first understand the network's concept of operations (CONOPS) and translate that into specifications, generally drawn from mature technologies, and in certain cases, newer or innovative approaches available to the designer within the allowable risk to the project. The authors submit that placing technology before the CONOPS introduces unappreciated risk into a system solution and omits essential iterative steps in defining the initial system requirements. When a specific technology drives the CONOPS, it sets the system requirements and makes overall performance contingent on the technology's maturity, allowing the specifications to reflect the optimum achievable reliability. This paper advocates rigorous development of the application CONOPS as the first priority, then selecting specifications and technological solutions that achieve risk, cost, and other programmatic requirements. One key risk and cost element common to sub-sea networks is that of cable termination technologies, and this paper presents alternatives to commonly used connector form-factors that can provide system designs alternative solutions to achieve desired CONOPS results.
{"title":"Connect or terminate: How CONOPS drives design of sub-sea network systems","authors":"M. Slater, J. Snyder","doi":"10.1109/OCEANS.2008.5152020","DOIUrl":"https://doi.org/10.1109/OCEANS.2008.5152020","url":null,"abstract":"The international emphasis on climate change has prompted numerous initiatives in ocean observation. These initiatives require the widespread use of undersea networks for scientific research. The resulting demand for reliable sub-sea networks installed in a variety of environments poses dramatic design challenges. Designers draw solutions from academic networks such as MARS and VENUS, commercial networks linking oil platforms, and military surveillance systems or undersea ranges. To meet user requirements and answer the technical challenges, system implementers must first understand the network's concept of operations (CONOPS) and translate that into specifications, generally drawn from mature technologies, and in certain cases, newer or innovative approaches available to the designer within the allowable risk to the project. The authors submit that placing technology before the CONOPS introduces unappreciated risk into a system solution and omits essential iterative steps in defining the initial system requirements. When a specific technology drives the CONOPS, it sets the system requirements and makes overall performance contingent on the technology's maturity, allowing the specifications to reflect the optimum achievable reliability. This paper advocates rigorous development of the application CONOPS as the first priority, then selecting specifications and technological solutions that achieve risk, cost, and other programmatic requirements. One key risk and cost element common to sub-sea networks is that of cable termination technologies, and this paper presents alternatives to commonly used connector form-factors that can provide system designs alternative solutions to achieve desired CONOPS results.","PeriodicalId":113677,"journal":{"name":"OCEANS 2008","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124881630","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}
Pub Date : 2008-09-01DOI: 10.1109/OCEANS.2008.5152104
F. Driscoll, G. Alsenas, P. Beaujean, S. Ravenna, J. Raveling, E. Busold, C. Slezycki
Florida is faced with an energy crisis with respect to capacity, supply, cost, emissions, and stability. The untapped energetic waters of the Florida Current could provide a clean, reliable, base-load local renewable energy source for Florida. To facilitate the successful commercial harvesting of this hydrokinetic resource, Florida Atlantic University's Center for Ocean Energy Technology is designing, fabricating, deploying, and operating an experimental small-scale turbine. This 20 kW Ocean Current Turbine Testbed (OCTT) is an open-blade axial-flow horizontal underwater turbine driven by a 3 m diameter 3-blade rotor. It is intended to operate in the open ocean near the core of the Florida Current, offshore Ft. Lauderdale, for long periods of time. This turbine is not intended to be a scaled prototype of a commercial model, but it is intended to be an experimental system to assess technology, identify gaps, investigate and collect data about potential environmental impacts, and provide a foundation for commercial and policy development.
{"title":"A 20 KW open ocean current test turbine","authors":"F. Driscoll, G. Alsenas, P. Beaujean, S. Ravenna, J. Raveling, E. Busold, C. Slezycki","doi":"10.1109/OCEANS.2008.5152104","DOIUrl":"https://doi.org/10.1109/OCEANS.2008.5152104","url":null,"abstract":"Florida is faced with an energy crisis with respect to capacity, supply, cost, emissions, and stability. The untapped energetic waters of the Florida Current could provide a clean, reliable, base-load local renewable energy source for Florida. To facilitate the successful commercial harvesting of this hydrokinetic resource, Florida Atlantic University's Center for Ocean Energy Technology is designing, fabricating, deploying, and operating an experimental small-scale turbine. This 20 kW Ocean Current Turbine Testbed (OCTT) is an open-blade axial-flow horizontal underwater turbine driven by a 3 m diameter 3-blade rotor. It is intended to operate in the open ocean near the core of the Florida Current, offshore Ft. Lauderdale, for long periods of time. This turbine is not intended to be a scaled prototype of a commercial model, but it is intended to be an experimental system to assess technology, identify gaps, investigate and collect data about potential environmental impacts, and provide a foundation for commercial and policy development.","PeriodicalId":113677,"journal":{"name":"OCEANS 2008","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124961003","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}
Pub Date : 2008-09-01DOI: 10.1109/OCEANS.2008.5151847
J. Flory, H. McKenna
This paper is a survey of four recently published guides for the inspection and retirement of fiber ropes, as used for marine hawsers, mooring lines, and other purposes. It is intended to bring these to the attention of marine personnel and others who should be concerned with rope inspection and retirement. Proper inspection and timely retirement of fiber ropes is crucial to avoid personnel injury, death, property damage, and pollution. Most past guides dealt only with generalities and were not very useful. These new guides give specific examples and quantitative criteria for at least some types of rope. This paper briefly summarizes some of the rope inspection and retirement methods and criteria provided in these guides. It includes the authors' experience and advice. It makes reference to other relevant guidelines and technical papers.
{"title":"Fiber rope inspection and retirement guides","authors":"J. Flory, H. McKenna","doi":"10.1109/OCEANS.2008.5151847","DOIUrl":"https://doi.org/10.1109/OCEANS.2008.5151847","url":null,"abstract":"This paper is a survey of four recently published guides for the inspection and retirement of fiber ropes, as used for marine hawsers, mooring lines, and other purposes. It is intended to bring these to the attention of marine personnel and others who should be concerned with rope inspection and retirement. Proper inspection and timely retirement of fiber ropes is crucial to avoid personnel injury, death, property damage, and pollution. Most past guides dealt only with generalities and were not very useful. These new guides give specific examples and quantitative criteria for at least some types of rope. This paper briefly summarizes some of the rope inspection and retirement methods and criteria provided in these guides. It includes the authors' experience and advice. It makes reference to other relevant guidelines and technical papers.","PeriodicalId":113677,"journal":{"name":"OCEANS 2008","volume":"138 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133233610","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}
Pub Date : 2008-09-01DOI: 10.1109/OCEANS.2008.5151947
O. Carrière, J. Hermand, J. Candy
In the context of the recent Maritime Rapid Environmental Assessment sea trial (MREA/BP'07), this paper presents a range-resolving tomography method based on the ensemble Kalman filtering (EnKF) of full-field acoustic measurements on a vertical array. The measurements are assimilated in a Gauss-Markov model of the sound-speed field time variations with known statistics. The reformulation of the inverse problem in an ocean data assimilation framework enables the sequential tracking of time- and space-varying environmental parameters. The tracking scheme is here applied to a realistic simulation of a vertical slice in a shallow water environment. Sea-surface sound-speed measurements are augmented to the measurement vector to constrain the range-dependent structure. Known bottom and subbottom properties are taken into account in the propagation model. When compared to the extended Kalman filter, the EnKF is shown to properly cope with the nonlinearity introduced by the full-field approach.
{"title":"Range-resolving shallow water acoustic tomography by ensemble Kalman filtering","authors":"O. Carrière, J. Hermand, J. Candy","doi":"10.1109/OCEANS.2008.5151947","DOIUrl":"https://doi.org/10.1109/OCEANS.2008.5151947","url":null,"abstract":"In the context of the recent Maritime Rapid Environmental Assessment sea trial (MREA/BP'07), this paper presents a range-resolving tomography method based on the ensemble Kalman filtering (EnKF) of full-field acoustic measurements on a vertical array. The measurements are assimilated in a Gauss-Markov model of the sound-speed field time variations with known statistics. The reformulation of the inverse problem in an ocean data assimilation framework enables the sequential tracking of time- and space-varying environmental parameters. The tracking scheme is here applied to a realistic simulation of a vertical slice in a shallow water environment. Sea-surface sound-speed measurements are augmented to the measurement vector to constrain the range-dependent structure. Known bottom and subbottom properties are taken into account in the propagation model. When compared to the extended Kalman filter, the EnKF is shown to properly cope with the nonlinearity introduced by the full-field approach.","PeriodicalId":113677,"journal":{"name":"OCEANS 2008","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132994239","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}
Pub Date : 2008-09-01DOI: 10.1109/OCEANS.2008.5151930
Z. Bai, Z. Wen, J. Wiltshire
A new type of water-dispersive anticorrosive paint was prepared by using marine cobalt-rich crusts tailings which are the residue of cobalt-rich manganese crusts after the extraction of Co, Ni, Cu, Zn, Mn by acid leach. The first step making the paint is preparing the colored slurry by mixing the tailings (54.65%, mass) with water (40.78%) and some auxiliary materials (4.57%). The second step is mixing the colored slurry (40%) with a styrene-acrylate copolymer (40%), water (11.9%) and some auxiliary materials (8.1%). Test results indicate that the resistance to impact of the coating film is equal to or more than 490 Nmiddotcm, the resistance to saline water is more than 24 days. The tailings can provide both physical and chemical corrosion protection. With their fine particle size the tailings can be dispersed into the styrene-acrylate copolymer to form a uniform coating film with relatively high bonding strength on surfaces to be protected. With a high Fe2O3 content the tailings provide physical cladding. With a high content of Sr and other trace elements the tailings can react with corroded ferrite or with other corrosive materials, such as S04 2-, to form unreactive oxides or inert compounds. In this way, the tailings serve as chemical preservation agents. P2O5 contained within the tailings may combine with metallic elements or may react with polar groups in the styrene-acrylate copolymer to form stable complex compounds to keep corrosion from developing. Oxidizing and reducing properties of rare earth elements may accelerate the formation of a polymer network of coating molecules and shorten both the solidifying and film-forming times for the coating. The tailings also likely enhance the strength and water resistance of the resultant coatings.
{"title":"Marine mineral tailings use in anticorrosive coatings","authors":"Z. Bai, Z. Wen, J. Wiltshire","doi":"10.1109/OCEANS.2008.5151930","DOIUrl":"https://doi.org/10.1109/OCEANS.2008.5151930","url":null,"abstract":"A new type of water-dispersive anticorrosive paint was prepared by using marine cobalt-rich crusts tailings which are the residue of cobalt-rich manganese crusts after the extraction of Co, Ni, Cu, Zn, Mn by acid leach. The first step making the paint is preparing the colored slurry by mixing the tailings (54.65%, mass) with water (40.78%) and some auxiliary materials (4.57%). The second step is mixing the colored slurry (40%) with a styrene-acrylate copolymer (40%), water (11.9%) and some auxiliary materials (8.1%). Test results indicate that the resistance to impact of the coating film is equal to or more than 490 Nmiddotcm, the resistance to saline water is more than 24 days. The tailings can provide both physical and chemical corrosion protection. With their fine particle size the tailings can be dispersed into the styrene-acrylate copolymer to form a uniform coating film with relatively high bonding strength on surfaces to be protected. With a high Fe2O3 content the tailings provide physical cladding. With a high content of Sr and other trace elements the tailings can react with corroded ferrite or with other corrosive materials, such as S04 2-, to form unreactive oxides or inert compounds. In this way, the tailings serve as chemical preservation agents. P2O5 contained within the tailings may combine with metallic elements or may react with polar groups in the styrene-acrylate copolymer to form stable complex compounds to keep corrosion from developing. Oxidizing and reducing properties of rare earth elements may accelerate the formation of a polymer network of coating molecules and shorten both the solidifying and film-forming times for the coating. The tailings also likely enhance the strength and water resistance of the resultant coatings.","PeriodicalId":113677,"journal":{"name":"OCEANS 2008","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132847658","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}
Pub Date : 2008-09-01DOI: 10.1109/OCEANS.2008.5151972
S. Silva, S. Cunha, A. Matos, N. Cruz
Height mapping of shallow water areas is an important task for many commercial and scientific applications like river navigability, infrastructure maintenance or natural resource monitoring. The use of an autonomous boat presents several advantages that ease the use of synthetic aperture images to create three-dimensional topographic maps through interferometric techniques. Sample data obtained during test trials illustrate how synthetic aperture can be used to generate imagery and bathymetry data.
{"title":"Shallow water height mapping with interferometric synthetic aperture sonar","authors":"S. Silva, S. Cunha, A. Matos, N. Cruz","doi":"10.1109/OCEANS.2008.5151972","DOIUrl":"https://doi.org/10.1109/OCEANS.2008.5151972","url":null,"abstract":"Height mapping of shallow water areas is an important task for many commercial and scientific applications like river navigability, infrastructure maintenance or natural resource monitoring. The use of an autonomous boat presents several advantages that ease the use of synthetic aperture images to create three-dimensional topographic maps through interferometric techniques. Sample data obtained during test trials illustrate how synthetic aperture can be used to generate imagery and bathymetry data.","PeriodicalId":113677,"journal":{"name":"OCEANS 2008","volume":"86 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116707236","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}
Pub Date : 2008-09-01DOI: 10.1109/OCEANS.2008.5151984
Hailiang Tao, G. Hickman, J. Krolik
Combining multiple beamforming outputs from different orientations of a linear array to obtain a full 2-D field directionality is investigated in this paper. A wavefield sampling method is proposed that could be effective at eliminating left-right ambiguity, reducing resolution problems at endfire directions, and suppressing background noise. Simulation results suggest that this wavefield sampling method could improve the probability of detection of weak directional sources. The method is compared with previous methods and is shown to have resolution and computation advantages.
{"title":"Field directionality synthesis from multiple array orientations: A least squares approach","authors":"Hailiang Tao, G. Hickman, J. Krolik","doi":"10.1109/OCEANS.2008.5151984","DOIUrl":"https://doi.org/10.1109/OCEANS.2008.5151984","url":null,"abstract":"Combining multiple beamforming outputs from different orientations of a linear array to obtain a full 2-D field directionality is investigated in this paper. A wavefield sampling method is proposed that could be effective at eliminating left-right ambiguity, reducing resolution problems at endfire directions, and suppressing background noise. Simulation results suggest that this wavefield sampling method could improve the probability of detection of weak directional sources. The method is compared with previous methods and is shown to have resolution and computation advantages.","PeriodicalId":113677,"journal":{"name":"OCEANS 2008","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116605174","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}
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