2012 Oceans最新文献

{"title":"Feasibility of underwater sensor networks for lifetime assessment of offshore civil structures","authors":"Jingcheng Li, S. Jang, M. Zuba, Jun-hong Cui, Yibo Zhu","doi":"10.1109/OCEANS.2012.6405087","DOIUrl":"https://doi.org/10.1109/OCEANS.2012.6405087","url":null,"abstract":"Recently, large-scale underwater ad-hoc networks and underwater sensor networks have drawn significant attention to explore vast possibilities in oceans. Many potential applications are possible using underwater sensor networks including biological habitat monitoring, energy harvesting and environmental monitoring. However, research on underwater structural monitoring has been limited. The focus of this paper is to investigate the feasibility of underwater sensor networks for offshore and deep-sea structural monitoring. In this paper, the network communication topology and in-network processing algorithm for two offshore wind farms, the Middelgrunden and Horn Revs offshore wind farms in Denmark, are considered based on numerical simulation using Aqua-Sim (an underwater simulation tool) for developing underwater sensor networks. An evaluation of a laboratory-scale water basin network experiments that make use of Aqua-Lab at University of Connecticut will be provided with possible future development for underwater civil infrastructure monitoring.","PeriodicalId":434023,"journal":{"name":"2012 Oceans","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123261625","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":"Advancements in high-performance timing for long term underwater experiments: A comparison of chip scale atomic clocks to traditional microprocessor-compensated crystal oscillators","authors":"A. Gardner, J. Collins","doi":"10.1109/OCEANS.2012.6404847","DOIUrl":"https://doi.org/10.1109/OCEANS.2012.6404847","url":null,"abstract":"We discuss the merits and performance of two commercially available time bases - a microprocessor-compensated crystal oscillator designed and manufactured by Seascan, Inc. of Falmouth, MA, and a chip-scale atomic clock (CSAC), designed and manufactured by Symmetricom, Inc. of San Jose, CA - for use in autonomous underwater instrumentation. Over the last ~10 years, the WHOI Ocean Bottom Seismology group has used the Seascan time base in its fleet of ~100 Ocean-Bottom Seismographs (OBS), and has acquired a record of Seascan performance amounting to over 183 cumulative seafloor years and over 25 years of cumulative test time in a temperature-chamber across 120 clocks. These data show that the Seascan clocks perform within their quoted specification in almost all cases, and if carefully selected can provide performance significantly exceeding their specifications, all at a very modest 5 mW of power consumption. Our testing has also shown some unexpected effects in certain units that may undermine timing quality if not understood and controlled. Within the last year or so, chip-scale atomic clocks have become available, and we have installed these time bases in 15 OBS. These CSACs offer two orders of magnitude improvement in precision, at the cost of significantly greater power consumption (~120 mW). We have deployed thirteen instruments on the ocean floor for a 6-month experiment using CSACs as the time base. In addition we have tested 4 more units in the lab. Based on the performance that we have seen in the field and in the lab, both time bases are worthy of consideration in new ocean instrumentation. As expected, the CSACs show better stability, lower aging, and better temperature response, at the expense of higher power consumption. This paper will present a detailed comparison of both clocks, showing the tradeoffs that need to be considered when selecting a time base. We will also look at techniques available to improve the aggregate performance of the Seascan time bases to well above their nominal specifications.","PeriodicalId":434023,"journal":{"name":"2012 Oceans","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114919951","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":"Aquarius/SAC-D Microwave Radiometer brightness temperature validation","authors":"A. Santos-Garcia, S. Biswas, L. Jones","doi":"10.1109/OCEANS.2012.6404830","DOIUrl":"https://doi.org/10.1109/OCEANS.2012.6404830","url":null,"abstract":"The Microwave Radiometer (MWR) on-board Aquarius/SAC-D is part of a joint international science mission between the National Aeronautics and Space Administration (NASA) and the Argentine Space Agency (Comision Nacional de Actividades Espaciales, CONAE). MWR, developed by CONAE, is a three channel Dicke radiometer operating at 23.8 GHz H-Pol and 36.5 GHz V-& H-Pol. This instrument complements the prime sensor, Aquarius L-band radiometer/scatterometer, by providing simultaneous spatially collocated environmental measurements such as integrated atmospheric water vapor, ocean surface wind speed, oceanic rain rate, and sea ice concentration, which aid in retrieving accurate Sea Surface Salinity. This paper presents the post-launch brightness temperature (Tb) validation, which was conducted using the CFRSL XCAL approach for inter-satellite radiometric comparison with the US Navy's WindSat radiometer during the first 10 months of MWR on-orbit measurements.","PeriodicalId":434023,"journal":{"name":"2012 Oceans","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122493187","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":"Design and testing of a Self-Mooring AUV","authors":"B. McCarter, R. Briggs, S. Portner, D. Stilwell, W. Neu, R. Coe, R. Duelley, D. Malley, J. Mims","doi":"10.1109/OCEANS.2012.6405053","DOIUrl":"https://doi.org/10.1109/OCEANS.2012.6405053","url":null,"abstract":"The Virginia Tech Self-Mooring AUV is capable of mooring itself on the seafloor. Its principal mission is to deploy bottom-mounted sensors without the need for a support ship to visit the mooring location. The mooring concept was previously demonstrated using a small-scale prototype. It has, more recently, been transitioned to a full-scale system and successfully demonstrated in the field. In this paper, we document the design of the full-scale vehicle and present results from field trials.","PeriodicalId":434023,"journal":{"name":"2012 Oceans","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114548477","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":"Jetski-based bathymetric surveying in Rincón, Puerto Rico","authors":"P. Chardon, M. Canals","doi":"10.1109/OCEANS.2012.6404950","DOIUrl":"https://doi.org/10.1109/OCEANS.2012.6404950","url":null,"abstract":"Puerto Rico is an island with a highly energetic wave climate and extreme surf zone hydrodynamics, which dominate sediment transport and coastal erosion. These effects can be monitored by conducting detailed bathymetric surveys to analyze extreme events. A jetski-based bathymetric surveying system was developed to navigate in the surf zone and be able to navigate in very shallow water. The system includes and single beam echo sounder, a side scan unit, and a highly sensitive GPS receiver, all of which are powered by a solar panel mounted in the jetski. Bathymetric surveys were performed in the municipality of Rincón in the island of Puerto Rico to observe morphological changes in the surf zone. This municipality has suffered from severe erosion during the last several decades. Using the bathymetric surveying system, semi-weekly cross-shore surveys were executed, demonstrating the system's capabilities for acquiring bathymetric data. This data was then compared to existing LIDAR bathymetric data for quality control purposes. After the initial surveying period, Puerto Rico was affected by Tropical Storm Isaac, which caused severe erosion in the coast of Rincón. Employing the platform, surveys were executed before and after the storm. Significant morphology changes were observed as a response of wave forcing, and cross-shore transects were analyzed to understand the damage caused and where the eroded sediment was deposited in the nearshore region.","PeriodicalId":434023,"journal":{"name":"2012 Oceans","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122047235","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":"Non-recurrent wideband continuous active sonar","authors":"G. Hickman, J. Krolik","doi":"10.1109/OCEANS.2012.6405101","DOIUrl":"https://doi.org/10.1109/OCEANS.2012.6405101","url":null,"abstract":"This paper presents a continuous active sonar (CAS) waveform which enables high revisit rates and wideband processing gains to be achieved with suppression of range-ambiguous returns. Non-recurrent wideband linear FM signals with circular Costas frequency-staggering across chirp repetition intervals is shown to provide ambiguity functions with good Doppler and range resolution, controllable Doppler and range ambiguities, and a high revisit rate. These slow-time Costas or “SLO-CO” CAS waveforms allow for the possibility of updating range-velocity estimates every pulse repetition interval while achieving the clutter suppression associated with the use of conventional wideband LFM signals.","PeriodicalId":434023,"journal":{"name":"2012 Oceans","volume":"140 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122047766","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":"A sequential filtering technique for geoacoustic inversion with ship of opportunity and a vector sensor","authors":"Qunyan Ren, J. Hermand","doi":"10.1109/OCEANS.2012.6405067","DOIUrl":"https://doi.org/10.1109/OCEANS.2012.6405067","url":null,"abstract":"This paper introduces a sequential filtering technique to obtain the ocean bottom acoustic properties with the noise field of a ship of opportunity. It filters the ratio between pressure p and vertical particle velocity Vz (or pressure gradient pg), both measured by a vector sensor, to estimate the environmental properties. This technique models the inverse problem as a random walk for the environmental time/spatial evolution, by formulating the environmental parameters in a recursive state-space form. It assumes the environmental parameters as the summation of previous stage parameters with a noise variance term for each state, and estimates their values along the source ship track by sequentially filtering recorded ship noise data. Numerical tests were carried out for the South East Elba environment. The preliminary results demonstrates this technique can effectively resolve most geoacoustic parameters.","PeriodicalId":434023,"journal":{"name":"2012 Oceans","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122091698","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":"Integrating Observing Systems to benefit stakeholders: A case study in the Gulf of Mexico","authors":"A. Jochens, M. Howard, L. Campbell, R. Mullins-Perry, G. Kirkpatrick, B. Kirkpatrick, C. Simoniello, Chuanmin Hu, R. Weisberg, C. Lembke, A. Corcoran, J. Ivey, S. Wolfe","doi":"10.1109/OCEANS.2012.6405030","DOIUrl":"https://doi.org/10.1109/OCEANS.2012.6405030","url":null,"abstract":"The U.S. Integrated Ocean Observing System is being designed to be an end-to Dend, integrated, sustained, operational System of Systems that provides data, information and products to benefit a broad range of stakeholders in their decision-making. These design concepts form the basis of pilot projects being undertaken by the Gulf of Mexico Coastal Ocean Observing System Regional Association (GCOOS-RA). This paper presents a case study of the GCOOS-RA Harmful Algal Bloom Integrated Observing System (HABIOS) Project. A set of research activities related to harmful algal blooms is examined for eventual transition from pilot project to an integrated operational system. The end-to-end nature of the system is explored from the perspectives of design and operation, data management and communication, modeling and analysis, decision-support tools and outreach, and benefits to stakeholders at national, regional, state, and local levels. The case study of the HABs pilot projects will demonstrate that HAB-related observations need to be both sustained and operational, and that progress is being may through the integration of the efforts of many entities concerned with detecting and monitoring HAB events and mitigating HAB impacts.","PeriodicalId":434023,"journal":{"name":"2012 Oceans","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128656683","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":"IBuoy: Expendable short time duration wave buoy with satellite data telemetry","authors":"D. Porter, K. Keller","doi":"10.1109/OCEANS.2012.6404838","DOIUrl":"https://doi.org/10.1109/OCEANS.2012.6404838","url":null,"abstract":"A prototype expendable wave buoy, the IBuoy, was designed, built, and deployed. The initial design of the system, its processing algorithm, sea test results, and future modifications are presented in this paper. In addition a modified IBuoy was deployed in Spring 2012 in the Arctic with the capability to measure the depth of the seafloor below the ice.","PeriodicalId":434023,"journal":{"name":"2012 Oceans","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129250284","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":"Multi-sensor evaluation of microwave water level measurement error","authors":"J. Boon, R. Heitsenrether, W. Hensley","doi":"10.1109/OCEANS.2012.6405079","DOIUrl":"https://doi.org/10.1109/OCEANS.2012.6405079","url":null,"abstract":"A microwave radar water level sensor, the Design Analysis Waterlog H-3611 has recently entered service at tide stations operated by the National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS), Center for Operational Oceanographic Products and Services (CO-OPS) as part of the National Water Level Observation Network (NWLON). The microwave water level sensor combines high accuracy with low sensitivity to variations in air temperature and humidity but differs from other water level sensors in utilizing an unconfined radar beam aimed vertically downward to the water surface. Many potential benefits of using microwave radar sensors for short-term flood advisories and long-term sea level monitoring have been identified by several organizations throughout the ocean observing community. The most notable advantage of radar sensors is their ability to measure water level remotely with no parts directly in contact with the water column. Water level measurement stations that employ remote radar sensor technology will avoid many problems typical of long-term subsurface ocean sensors including biological fouling and corrosion. Remote sensing also results in a significant reduction in system hardware components and overall installation and maintenance requirements. Results from a series of laboratory and field tests conducted by CO-OPS over the last few years have led to operational use of Waterlog radar units in certain specific applications. It is acknowledged, however, that most test data collected and analyzed to date for the purpose of assessing the sensor's capabilities have focused on enclosed coastal regions with limited fetch and a low-wave environment (average significant wave height nominally less than 1 m). Although these test results are relevant to many CO-OPS applications of interest, including the majority of NWLON stations located in low-wave environments, uncertainty remained after the initial test phase and led to a new outlook toward sensor performance in open ocean environments that experience significant wave heights frequently in excess of 1 m. Additional testing under these conditions has presented a greater challenge as both the test and reference NWLON sensors are likely to encounter limitations in the presence of large waves. Analytical tools including spectral analysis of sensor output signals and an evaluation of sample statistics were needed to better understand the nature of these limitations. In order to address the remaining uncertainty in sensor performance capability, a multi-sensor test deployment was recently conducted at an open-ocean test site, the U.S. Army Corps of Engineers Field Research Facility at Duck, NC (Duck FRF). The resulting multi-sensor data set has allowed sensor measurement error to be estimated for the first time from measurement residuals about an ensemble average series. Comparing ensemble-based error estimates with corresponding Duck FRF nearshore wave data averaged over sel","PeriodicalId":434023,"journal":{"name":"2012 Oceans","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124629849","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}