OCEANS '02 MTS/IEEE最新文献

{"title":"A portable, electronic-focusing sonar system for AUVs using 2D sparse-array technology","authors":"A. Chiang, S. R. Broadstone, J. Impagliazzo","doi":"10.1109/OCEANS.2002.1191960","DOIUrl":"https://doi.org/10.1109/OCEANS.2002.1191960","url":null,"abstract":"Jeralech Corporation is developing an electronic-sonar system for 3D imaging to be integrated into low power, compact marine vehicles. This sonar system fulfills operational requirements for mine identification while preserving the vehicle's ability to conduct extended range missions. The capability of the sonar is a result of the development of application specific integrated circuits based on Teratech's proprietary Charge Domain Processing (CDP) technology. The intended application is for reconnaissance in shallow and very-shallow waters.","PeriodicalId":431594,"journal":{"name":"OCEANS '02 MTS/IEEE","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122629976","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":"Observing sea surface salinity in coastal domains using an airborne surface salinity mapper","authors":"D. Burrage, J. Miller, D. Johnson, J. Wesson, J. Johnson","doi":"10.1109/OCEANS.2002.1191942","DOIUrl":"https://doi.org/10.1109/OCEANS.2002.1191942","url":null,"abstract":"Sea Surface Salinity directly affects the status of coastal ecosystems and serves as a tracer for seawater constituents associated with freshwater runoff. As part of an NRL-sponsored study of the dynamics of coastal buoyancy jets (CoJet), which began in July, 2000, the original Scanning Low Frequency Microwave Radiometer (SLFMR) was deployed in various coastal locations to evaluate its performance for mapping sea surface salinity, and demonstrate its application to studies of coastal plumes and buoyant jets. In a sequence of three campaigns, the radiometer was flown repeatedly over the Cheseapeake and Mobile Bay plumes and over the northern Gulf of Mexico and Florida Bay using a twin-engine Piper Navajo aircraft. Extensive surveys of sea surface salinity distributions were conducted on time scales of a few hours. The instrument was field calibrated using in situ data from oceanographic research vessels and the resulting salinity maps were corrected for known environmental influences. The logistical convenience and broad dynamic range of the instrument allowed surface maps to be generated quickly over waters that were either significantly fresher or more saline than standard seawater. The instrument performance and resulting map quality were thus found to meet the requirements of coastal oceanographic studies that are characterized by large buoyancy signals, and a variety of forcing effects that evolve relatively rapidly in time and space. The instrument and data processing system are first described and two new methods of field calibration method are presented. Examples of surface salinity maps of rapidly evolving coastal plume features are then described and interpreted using supporting in situ data. Finally, the overall capability and utility of the system is evaluated, and recent advances in the technology and future prospects are briefly considered.","PeriodicalId":431594,"journal":{"name":"OCEANS '02 MTS/IEEE","volume":"171 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122872306","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":"Underwater robot navigation using benthic contours","authors":"M. Rendas, S. Rolfes","doi":"10.1109/OCEANS.2002.1193287","DOIUrl":"https://doi.org/10.1109/OCEANS.2002.1193287","url":null,"abstract":"This paper presents results on the navigation of mobile underwater robots using maps of contours of distinct habitats of the sea-floor. The contour maps are acquired by autonomously tracking the boundaries of contrasting regions of the sea bed using a video camera mounted on the robot. Recognition of previously seen regions enable the robot to reset dead-reckoning errors, enabling consistent position estimates to be maintained.","PeriodicalId":431594,"journal":{"name":"OCEANS '02 MTS/IEEE","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123794832","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":"Automatic man-made object detection with intensity cameras","authors":"A. Olmos, E. Trucco, D. Lane","doi":"10.1109/OCEANS.2002.1191867","DOIUrl":"https://doi.org/10.1109/OCEANS.2002.1191867","url":null,"abstract":"We present a system detecting the presence of man-made objects in unconstrained subsea videos. This presents a significant challenge because nothing is assumed about the possible orientation or location of the objects and because of the generally poor underwater image quality. Classification is based on contours, which are reasonably stable features in underwater imagery. First, the system determines automatically an optimal scale for contour extraction by optimising a quality metric. Second, a classifier determines whether the image contains man-made objects or not. The features used capture general properties of man-made structures using measures inspired by perceptual organisation. Using a Support Vector Machines (SVM) classifier the system classified correctly approximately 77% of the image-frames containing man-made objects belonging to five different underwater videos, in spite of the varying image contents, poor quality and generality of the classification task.","PeriodicalId":431594,"journal":{"name":"OCEANS '02 MTS/IEEE","volume":"107 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123991037","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 automatic meteorological data collection system that is installed at Global Positioning System monitoring stations","authors":"E. Michelena, S. Gutman","doi":"10.1109/OCEANS.2002.1191927","DOIUrl":"https://doi.org/10.1109/OCEANS.2002.1191927","url":null,"abstract":"The Demonstration Division of NOAA's Forecast Systems Laboratory is conducting a long-term experiment to test the effectiveness of using the precise geodetic position measurements made by a network of Global Positioning System monitoring stations to determine the total amount of water vapor contained in the sectional volume of the atmosphere above each station. By knowing the exact position of the GPS satellites along their orbits and the precise location of the GPS monitoring receivers on the ground, an interpretation of the location error (actual location versus receiver-derived apparent location) yields a good indication of the amount of water vapor in the atmosphere. This result occurs because the monitoring station's apparent location error is partially caused by the water vapor. Many factors influence the propagation of the electromagnetic waves as they travel through the Earth's atmosphere from the constellation of GPS satellites (distributed along their orbits) to the GPS monitoring receivers (distributed throughout a ground surface network). One of these factors is the total amount of atmospheric water vapor. It is the quantity of this water vapor that the Demonstration Division is measuring. Other factors that affect the local speed of propagation of the electromagnetic waves transmitted from the GPS satellites, as the waves travel toward the GPS ground receivers, are the degree of ionization of the Ionosphere and the mass density distribution of the air in the Atmosphere. By subtracting the effects of the ionization and of the mass density distribution from the monitoring station's total position error, the fraction of the total error caused by atmospheric water vapor can be isolated. With this value, the quantity of water vapor in the atmosphere can be calculated. The effect of the mass-density distribution of the atmosphere can be more precisely determined if its pressure, temperature, and relative humidity are accurately measured at the GPS monitoring stations. For this purpose, special meteorological data-collection systems have been installed at the same sites where GPS monitoring receivers are providing position-error data. These automatic systems were designed and built by the National Data Buoy Center. In them a microcontroller provides two-way data communication with a digital barometer and with a digital temperature/humidity sensor. The microcontroller also manages the digital interrogations and replies necessary for the transmission of the meteorological data to a central collection station at the Forecast Systems Laboratory in Boulder, Colorado. This data communication is via existing digital circuits used by the U.S. Coast Guard and by the National Geodetic Survey for monitoring and controlling the Differential Global Positioning System Aids-to-Navigation network. The meteorological data collection electronic packages and supporting hardware are called GPS Surface Observing Systems (GSOS). They can be quickly and easily in","PeriodicalId":431594,"journal":{"name":"OCEANS '02 MTS/IEEE","volume":"61 3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125563477","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":"Pipe MAVS, a deep-ocean flowmeter","authors":"A. Williams, T. Bjorklund, A. Zemanovic","doi":"10.1109/OCEANS.2002.1192056","DOIUrl":"https://doi.org/10.1109/OCEANS.2002.1192056","url":null,"abstract":"An acoustic differential travel-time current sensor with 6000-m depth capability has been adapted to measure flow in a pipe, initially for hydrothermal vent flow studies. The acoustic measurement path, 9.8 cm long, is inclined 18 degrees to the axis of a 20.3-cm inside diameter stainless steel pipe. The integrated component of flow along the acoustic axis is resolved to 0.04 cm/s with a standard deviation noise level near zero flow corresponding to 0.09 cm/s. that makes a threshold of detection of 0.45 cc/s or 0.03 liters/minute. The upper limit of flow that can be measured is 60 liters/minute. Uniform weighting of the measurement of velocity across the diameter of the pipe means that the annulus of fluid near the wall is underrepresented compared to the core of the fluid near the center. Therefore the radial profile of velocity enters into the calibration of the flowmeter. Furthermore, the profile depends on Reynolds number and the roughness of the boundary layer in the pipe. Flow measurements are important when a fluid source is diffuse yet the total volume and rate of flow of the source is needed. In the case of hydrothermal vents, the heat output of a diffuse vent requires both the temperature anomaly and the volume of fluid to be measured. In Pipe MAVS, three thermistors are provided: one to measure the external ambient temperature, and two inside the pipe to measure the temperature at the inlet and the outlet. A collecting structure covering the diffuse source concentrates the flow to be measured by Pipe MAVS. Since measurements are made rapidly, fluctuations in total flow are resolved and can be integrated for any period of interest to remove artifacts of the collector yet reveal variability in the flow. Momentarily closing the pipe establishes the zero offset in situ. Applications of Pipe MAVS to measure shallow water sources of fresh water in marshes and in coastal regions and of flow in either direction through a porous sea-floor are possible within the limits of the zero point resolution. Amplification of flow by increasing collection area is a better way to increase sensitivity than to decrease cross sectional area in the pipe. Pipe MAVS, with its 6000-m depth rating, can supplement current and temperature measurements in monitoring hydrothermal vent energetics.","PeriodicalId":431594,"journal":{"name":"OCEANS '02 MTS/IEEE","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126158229","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":"Assessing offshore vulnerabilities and counter-response capabilities using RapidOps","authors":"J. Harbour","doi":"10.1109/OCEANS.2002.1192133","DOIUrl":"https://doi.org/10.1109/OCEANS.2002.1192133","url":null,"abstract":"Offshore hydrocarbon exploration, production, and transport capabilities represent critical national and international energy assets and infrastructures. As such, ensuring their continued protection against a diverse array of threats represents a top priority among government and industrial organizations alike. A first step in offering such assurances is the ability to conduct realistic vulnerability assessments of these key offshore assets and to evaluate various response capabilities. A recently developed tool (RapidOPs) and associated method for evaluating vulnerabilities and response effectiveness is described. RapidOps links time- and probability-based modeling in a graphic, intuitive, easy-to-use, and field deployable computer-assisted environment. This paper summarizes the basic concepts associated with assessing vulnerabilities and counter-response capabilities, especially related to deliberate, malevolent attacks. It then describes and illustrates the salient and applicable features of RapidOps and demonstrates how it can be specifically applied to assessing offshore vulnerabilities and response capabilities.","PeriodicalId":431594,"journal":{"name":"OCEANS '02 MTS/IEEE","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129928696","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":"Water-level and directional wave data collection in Mississippi Sound and the Gulf of Mexico near Pascagoula, MS","authors":"W. Corson, J. Rhee, L. Lillycrop, P. Robinson","doi":"10.1109/OCEANS.2002.1193323","DOIUrl":"https://doi.org/10.1109/OCEANS.2002.1193323","url":null,"abstract":"In support of the U.S. Army Engineer District, Mobile's Pascagoula Harbor dredged material management plan studies, two directional (DWG) and one non-directional wave gages were deployed offshore of Pascagoula MS. MS00N (the non-directional gage) and MS002 (a DWG; were deployed adjacent to Pascagoula Channel range marker \"B\" platform. MS001 (also a DWG) was deployed in the Gulf of Mexico approximately 2,000 ft offshore of Petit Bois Island, near Horn Island Pass. The data were used in an assessment of the validity of numerically generated estimates. The data also provide details of vessel wakes for the location adjacent to the channel.","PeriodicalId":431594,"journal":{"name":"OCEANS '02 MTS/IEEE","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129451642","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":"Real-time classification of buried targets with teams of unmanned vehicles","authors":"J. Edwards","doi":"10.1109/OCEANS.2002.1193290","DOIUrl":"https://doi.org/10.1109/OCEANS.2002.1193290","url":null,"abstract":"Recent rapid developments in autonomous underwater vehicle (AUV) technology have provided the opportunity to explore new approaches for detecting and classifying mine-like objects. In particular, the mobility of the vehicles the spatial diversity of the target scattering can be of advantage. The multi-platform approach can also lead to detection and classification algorithms that require significantly less computation than traditional sonar techniques, and as such these algorithms are more readily implementable in real-time onboard the vehicles. A method of target classification is shown in which the 3D scattered field is sampled by several receiver vehicles and information is extracted about the targets that clearly distinguish mines from rocks and rounded objects from oblong objects. The method is applicable to both buried and proud targets, and does not require the sub-wavelength accuracy navigation that is necessary for synthetic aperture sonar (SAS) imaging. The proposed classification method is shown to be easily implementable in real-time, as is demonstrated both in simulations and in post-processing experimental data from the 1998 generic oceanographic array technology sonar project (GOATS'98) experiment. Experimental data from the GOATS 2002 experiment are also presented.","PeriodicalId":431594,"journal":{"name":"OCEANS '02 MTS/IEEE","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124615489","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":"Performance metrics and skill assessment methods demonstrated using numerical model results for the Gulf of Mexico","authors":"H. J. Herring, J. Blaha","doi":"10.1109/OCEANS.2002.1192073","DOIUrl":"https://doi.org/10.1109/OCEANS.2002.1192073","url":null,"abstract":"Specific formulations for performance metrics to be used to compare model fields with various types of observation are proposed, including metrics that are appropriate for current meter data, hydrographic cast data, Lagrangian drifter data and satellite sea surface height and sea surface temperature data. The key element in the formulation of each of these metrics is the recognition of the fact that the salient features of the actual circulation may exist in the model fields but not always in the correct geographical location. Therefore, the proposed metrics record both the accuracy with which the model reproduces the feature, in the form of a correlation, and the relative location of the model simulated feature, in the form of a displacement. The result is considerably more informative and useful than the conventional comparison where a correlation between the data and the model field at the same geographical location is shown to be small and, therefore, the skill of the model is judged to be low. Also addressed is the essential difference between the data from in situ observations and variable fields calculated using a numerical model. An approximate method of treating the in situ data is proposed to make the comparison between in situ data and model results more meaningful.","PeriodicalId":431594,"journal":{"name":"OCEANS '02 MTS/IEEE","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130564440","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}