2012 Oceans最新文献

{"title":"Online speed optimization for sailing yachts using extremum seeking","authors":"Lin Xiao, J. Alves, N. Cruz, J. Jouffroy","doi":"10.1109/OCEANS.2012.6404876","DOIUrl":"https://doi.org/10.1109/OCEANS.2012.6404876","url":null,"abstract":"This paper briefly presents the main points on the development and testing of an extremum seeking controller used to maximize the longitudinal velocity of surface sailing vehicles by changing the angle of the sail. The algorithm is suitable for sailing purposes since it requires only the measurements of the vehicle's velocity and the sail angle. As an illustration, we present a few simulation results on our previously-obtained sailing yacht simulator, which was developed based on a 4 DOF nonlinear dynamic model for surface sailing vehicles, showing that the proposed extremum seeking controller is capable of maximizing the sailing yacht's speed performance through online sail tuning. Furthermore, the proposed sail optimization algorithm is tested at sea on an experimental platform, i.e. a small scale autonomous sailboat, illustrating the potential of the controller.","PeriodicalId":434023,"journal":{"name":"2012 Oceans","volume":"7 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":"114828950","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-hop time synchronization for Underwater Acoustic Networks","authors":"Chuan Sun, Feng Yang, Lianghui Ding, Liang Qian, Cheng Zhi","doi":"10.1109/OCEANS.2012.6404923","DOIUrl":"https://doi.org/10.1109/OCEANS.2012.6404923","url":null,"abstract":"Time synchronization plays an important role in UANs, which need fine-grained coordination among nodes. Precise time synchronization is also needed for a variety of other coordinate tasks in UANs such as data fusion, TDMA scheduling, localization, power-saving and so on. Recently, time synchronization protocol for point-to-point with high propagation delay has been proposed, while time synchronization for multi-hop UANs is still an open issue. In this paper, we propose a multi-hop time synchronization scheme for Underwater Acoustic Networks (MSUAN). MSUAN includes three stages. In the first stage, we assign each node a level by establishing a path to the reference node. During the second phase, nodes realize synchronization by receiving synchronization packets both from it's parent node and neighboring nodes. The third stage re-synchronizes nodes because the clock may drift away without synchronization for long time. Mathematical analysis of MSUAN's synchronization error shows that the more time-stamps we get, the more accurate skew we will get. At the end, we use OPNET to simulate MSUAN, and the simulation result under pyramid topology shows that even the hop accumulates to 8, for MSUAN, the average offset error is maintained at about 58us and the average skew error is below 2ppm.","PeriodicalId":434023,"journal":{"name":"2012 Oceans","volume":"73 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":"117080045","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":"Expanding the Caribbean Coastal Ocean Observing System into the nearshore region","authors":"M. Canals, J. Morell, J. Corredor, S. Leonardi","doi":"10.1109/OCEANS.2012.6404936","DOIUrl":"https://doi.org/10.1109/OCEANS.2012.6404936","url":null,"abstract":"After five years of continued development, the Caribbean Coastal Ocean Observing System (CariCOOS) has reached a major turning point regarding the nature of its ocean observing platforms and numerical modeling efforts. During the design stage of CariCOOS, stakeholder consultations highlighted the need for operational instrumented buoy platforms to provide data on winds, waves, currents and water quality. This led to the deployment of three full data buoys off the coasts of San Juan, Ponce and the United States Virgin Islands (USVI), a directional Datawell Waverider buoy in the Mona Passage, an array of shore based High Frequency Radar antennas for surface current mapping in the Mona Passage, and a network of 13 hurricane-hardened coastal meteorological stations. In addition, a suite of numerical models of winds and waves are currently operational for the region and continuously validated with our observational assets. Although stakeholders have expressed satisfaction with the regional-scale understanding obtained with CariCOOS models and ocean observing assets, recent consultations have highlighted the need for sector focused products to be developed at smaller scales targeting selected ports, highly visited and yet often hazardous tourist beaches, marine protected areas and other locations. Efforts in the current developmental stage are aimed in this direction; our mission consists of a combination of maintaining our suite of buoys, weather stations and numerical models with the development of new observing platforms and models to satisfy the nearshore-specific needs of our stakeholders. Despite being closer to shore, however, observing and predicting the complexity of the wind, wave and current patterns in the nearshore region requires highly specialized sensors and very high resolution numerical models. Stakeholder-driven efforts focused in the nearshore region currently underway at Cari-COOS include the development of a high-resolution jetski-based bathymetric surveying and side scan sonar system, a real-time surfzone currents and beach hazards warning system, and the implementation of a three-dimensional baroclinic circulation model for important ports and nearshore regions. In this paper we describe these and other new initiatives in detail and explain the design and development process.","PeriodicalId":434023,"journal":{"name":"2012 Oceans","volume":"7 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":"117317855","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":"Statistical properties of high frequency acoustic fluctuations induced by rough sea surface","authors":"M. R. Mousavi, M. Karimi, M. Farrokhrooz","doi":"10.1109/OCEANS.2012.6404826","DOIUrl":"https://doi.org/10.1109/OCEANS.2012.6404826","url":null,"abstract":"Probability Density Function (PDF) of the arrival angle and arrival time of high-frequency sound forward scattering from the rough sea surface are predicted by combining the ray-based and surface-based models. Empirical ocean wave spectrum and empirical model of the sea surface slope are used to model the surface-wave model. We show that environmental parameters and geometrical conditions influence the statistical properties of a wave forward-scattered from the sea surface. To show the validity of the approach, the results are compared with an experimental model. We observe that the proposed model is in good agreement with the expermentally obtained model.","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":"115770390","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":"Enabling technology: High capacity wet mateable optic Connection","authors":"Dave Jenkins, Matt Christiansen","doi":"10.1109/OCEANS.2012.6405124","DOIUrl":"https://doi.org/10.1109/OCEANS.2012.6405124","url":null,"abstract":"SEA CON® has raised the bar, with the recent introduction of a 8-48 channel Wet Mateable optic Connector (WMC). Based on the highly successful HydraLight wet mateable optic connector design, SEA CON's innovative design leverages the existing HydraLight components, and couples them with an existing multichannel insert, creating a high capacity, highly reliable optic wet mateable connector. This higher density WMC surely resets the bar for what is possible with undersea network architecture. The 24 channel version qualification is complete, with strong production interest from a number of market segments. This paper will provide a technical overview of this innovative product, and suggest possible applications. Key attributes include: Field proven sealing mechanism identical to the highly successful HydraLight design; APC contacts, configurable up to a maximum of 48; Combines HydraLight core design with multi-way insert from our successful G3 6 channel small form factor, wet mateable optic connector; Synthetic mineral oil compensation fluid; Fully compatible elastomers; Oil filled and pressure balanced design; Linear Latching and de-latching mechanism; Standard SEACON® Precision MKII PBOF 13mm Hose interface. This new product combines the highly desirable HydraLight wet mateable optic connector (over 3300 provided), with the multi-channel insert from our successful G3 downhole optical connector. A multi-channel optical insert allows each of the (up to) 8 HydraLight optical positions to be populated with a 6 way insert. This approach preserves the basic mechanics of the HydraLight, including the shells, seals and latching mechanism, and allows for a high density optical connection in a form factor identical to the current HydraLight connector. As is the case with the current HydraLight, the high capacity HydraLight can be equipped in either a ROV style, or a stab plate configuration. In addition, it may be configured with either oil filled hose, or hard cable. This highly innovative new product will be introduced, characterized, and then examples of how it can be used in a number of system applications will be discussed. This high capacity optical WMC is a game changer, and has the ability to reshape what can and cannot be done with subsea optical connectivity.","PeriodicalId":434023,"journal":{"name":"2012 Oceans","volume":"40 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":"123121675","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":"Combining interferometry soundings with angle uncertainty and signal to noise ratio into data processing for sea floor charting","authors":"Y. Ai, R. Allen","doi":"10.1109/OCEANS.2012.6405088","DOIUrl":"https://doi.org/10.1109/OCEANS.2012.6405088","url":null,"abstract":"In this article, we present a new development with test results on the sonar uncertainty model and the relevant processing of the interferometric bathymetry sounding data. Within a sonar sounding solution, not only an angle and time-delay pair is resolved, but quality factor, angle uncertainty and signal to noise ratio (SNR), with which the angle solution is obtained, are provided as well for the completeness of the data fields required for post processing. The goal is to generate a final sounding with registered uncertainties in three dimensions. As a result, the quality factor and SNR are applied to eliminate the low quality angle solutions due to backscatter from either multiple path or shadow area. The cleaned angle and time delay pair is then used for the estimation of the local depth, registered with the depth uncertainty derived from the angle uncertainty. The resolved depth plus its uncertainty, along with data from other sensors (IMU and SVP) and their related uncertainties, are processed by the Combined Uncertainty and Bathymetry Estimator (CUBE) [1] to generate a final mapping solution registered by a total propagated uncertainty to be checked against IHO S-44 at different order levels. From another view point, the SNR is a measurement of both the signal quality at each spatial sample and the coherence between the data streams from different bathymetric transducer receive staves. The coherence measurement is helpful to determine the valid angle apart from the nadir from which a robust sounding solution can be obtained in a full ping. It is evident that the SNR streams computed from different receiver pairs start to converge from an angle α apart from the nadir. The angle solutions within α would be considered as only fine quality due to the de-correlation introduced by different spacing among the receive staves. Conventionally, sonar manufacturers specify angles ~35 deg to start processing the data. However, with the new capability, α is determined from real-time data and is adaptively adjusted in situ based on the bottom, depth, motion, and other acoustic environments. First, a Sonar Uncertainty Model is presented. It is a Simulink (Matlab) package composed of Sonar Simulation Toolsets (Applied Physics Lab, University of Washington, Seattle), Klein Bathymetry Engine, and statistical processing. Second, in a cooperative effort with the Center for Coastal and Ocean Mapping/Joint Hydrographic Center (CCOM/JHC), sea trial data has been processed to evaluate the uncertainty model. Third, a full data set collected from Portsmouth, N.H. by a Klein HydroChart 5000 has been processed by CARIS through CUBE application. Analysis results are discussed and demonstrated.","PeriodicalId":434023,"journal":{"name":"2012 Oceans","volume":"34 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":"123667489","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 modes circular array superdirective beamforming","authors":"Yukang Liu","doi":"10.1109/OCEANS.2012.6405024","DOIUrl":"https://doi.org/10.1109/OCEANS.2012.6405024","url":null,"abstract":"Circular arrays are widely used in underwater acoustics array signal processing due to their two dimensional symmetrical characteristics. In this paper a new method to analytically calculate the superdirective mode coefficients of the phase modes circular array beamforming is proposed. The maximum Directivity Index (DI) achievable for phase modes circular array beamforming is also derived. Computer simulation is held for a circular array composed of 12 separate hydrophones mounted on either open sphere or rigid sphere. The calculated DI achieved by the proposed superdirective beamforming corresponds to the theoretical maximum DI for up to the 5th order. The proposed method to calculate the superdirective mode coefficients is also applicable for calculating mode coefficients for arrays of any shape and any kind of expansion, indicating its wide range of applications in superdirectivity beamforming.","PeriodicalId":434023,"journal":{"name":"2012 Oceans","volume":"38 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113958809","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":"Detection of harmonic signals","authors":"J. Piper, S. Reese, W. G. Reese","doi":"10.1109/OCEANS.2012.6404910","DOIUrl":"https://doi.org/10.1109/OCEANS.2012.6404910","url":null,"abstract":"Harmonic signals are often produced by man-made sources. Their detection has traditionally been accomplished by using Fourier methods. An alternative approach that uses a maximum likelihood function is presented in this paper. The power of this approach comes from modelling the received signal as a family of harmonic signals. This effectively reduces the problem to a one-dimensional search for the fundamental frequency. The coefficients for the various harmonic frequencies can then be found using the Moore-Penrose inverse.","PeriodicalId":434023,"journal":{"name":"2012 Oceans","volume":"14 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":"114959828","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":"Devising MIMO arrays for underwater 3-D short-range imaging","authors":"Liu Xiong-hou, Sun Chao, Zhuo Jie, Ma Qian, Pan Hao","doi":"10.1109/OCEANS.2012.6405062","DOIUrl":"https://doi.org/10.1109/OCEANS.2012.6405062","url":null,"abstract":"To reduce the sensor number and restrict the array size of an underwater 3-D imaging system, the multiple-input multiple-output (MIMO) array is adopted in this paper. The relationship between the narrowband or wideband MIMO array and its virtual array is discussed in detail and the analytical solution of the coordinates of the virtual sensors is given. Based on the ability of providing virtual sensors of MIMO arrays, several MIMO array layouts are proposed, which can be equivalent to the rectangular planar array, the cylindrical array and the spherical array, respectively. And plenty of sensors in these array layouts are saved. Moreover, some MIMO arrays which can reduce the sensor number and the array size simultaneously are also introduced.","PeriodicalId":434023,"journal":{"name":"2012 Oceans","volume":"28 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":"125371175","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":"Joint deployment of undersea sensors for enhanced maritime security at perimeters and choke points","authors":"R. Granger, B. J. Sikorski, C. Walker, E. Rabe","doi":"10.1109/OCEANS.2012.6404913","DOIUrl":"https://doi.org/10.1109/OCEANS.2012.6404913","url":null,"abstract":"The US Coast Guard, US Navy and other maritime and port security units routinely conduct undersea inspections for a variety of mission requirements. However, current inspection techniques only sample a small number of vessels transiting into US waters, resulting in limited situational awareness in the undersea domain and creating an opportunity for introduction of threatening devices into harbors where they can inflict great harm. The Naval Undersea Warfare Center (NUWC) Detachment San Diego, NUWC Division Newport, and Battelle have developed and demonstrated undersea systems that can be combined to address several of these mission requirements in a joint deployment, facilitating more efficient and complete harbor security. This paper will provide an overview of each system component, including hardware descriptions and test results to date, and discuss deployment Concept of Operations (CONOPS) at a candidate location.","PeriodicalId":434023,"journal":{"name":"2012 Oceans","volume":"52 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":"126265407","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}