OCEANS 2016 - Shanghai最新文献

{"title":"Blind channel estimation combined with matched field processing in underwater acoustic channel","authors":"W. Feng, Jianlong Li, Lan Zhang","doi":"10.1109/OCEANSAP.2016.7485513","DOIUrl":"https://doi.org/10.1109/OCEANSAP.2016.7485513","url":null,"abstract":"Blind channel estimation methods normally use the statistical properties of received signals to restore the original waveform without a priori information. However, these methods need a high computational complexity especially in multipath environments, and their performances are not good enough. A blind channel estimation method utilizing acoustic propagation physics via normal mode is proposed in this paper. Some environmental information and matched field processing (MFP) is used for source localization by matching array data to solutions of an ocean waveguide. This method could in theory acquire more accurate channel information and without requiring any information about transmitted signal. Numerical simulations are presented to demonstrate the accuracy and robustness of this method in multipath environments.","PeriodicalId":382688,"journal":{"name":"OCEANS 2016 - Shanghai","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115168704","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":"Deep water acoustic calibration facility: Development of a platform","authors":"J. Malan, A. Marouchos, M. Sherlock, Tim E. Ryan, Rudy J. Kloser","doi":"10.1109/OCEANSAP.2016.7485398","DOIUrl":"https://doi.org/10.1109/OCEANSAP.2016.7485398","url":null,"abstract":"Acoustic systems are used widely to provide quantitative estimates of biomass for fisheries and ecosystem assessments. Traditionally, these systems are attached to surface vessels, but increasingly they are being fitted to remote operated vehicles, autonomous vehicles and towed platforms. These platforms allow the acoustic transducer to get closer to targets, and provide increased resolution and, if calibrated, better accuracy of surveys at depth. To achieve better accuracy requires regular and methodical calibration of acoustic transducers at depth using calibration targets of a known acoustic signature. Standard methods exist for calibrating such systems just below the surface, but calibrating such systems at their operating depths is far more difficult. A bespoke system was necessary to allow scientists and technicians to calibrate acoustic transducers at their operating depths to quantify their characteristics and performance. This paper will discuss the design, development and testing of a DEepwater CAlibration Facility (DECAF). The design challenges are presented along with a discussion of difficulties in the operation of such a system.","PeriodicalId":382688,"journal":{"name":"OCEANS 2016 - Shanghai","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127775582","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 edge-based smoothed finite element method for two-dimensional underwater acoustic scattering problems","authors":"Wei Li, Qifan Zhang, Y. Chai, Tianyun Li, Zhixiong Gong","doi":"10.1109/OCEANSAP.2016.7485623","DOIUrl":"https://doi.org/10.1109/OCEANSAP.2016.7485623","url":null,"abstract":"An edge-based smoothed finite element method (ES-FEM) is presented that cures the \"overly-stiff\" property of the original standard finite element method (FEM) for the analysis of two-dimensional underwater acoustic scattering problems. In the ES-FEM model, the gradient of the acoustic pressure (the acoustic particle velocity) is smoothed and the numerical integration is implemented using Green's theorem and Gauss integration, then the discretized linear system equations are established using smoothed Galerkin weak form with smoothing domains associated with the edges of the triangular elements. Due to the proper softening effect provided by the edge-based gradient smoothing operation, a \"close-to-exact\" stiffness of the system can be obtained, and then the numerical dispersion error can be significantly decreased. In order to handle the underwater acoustic scattering problems in an infinite domain, the unbounded domain is truncated by an artificial boundary on which the well-known Dirichlet-to-Neumann (DtN) boundary condition is imposed to replace the Sommerfeld condition at infinity in this paper. Several numerical examples are investigated and the results show that the ES-FEM can achieve more accutate solutions compared to the standard FEM.","PeriodicalId":382688,"journal":{"name":"OCEANS 2016 - Shanghai","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133744716","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 vessel towed platform for deepwater high resolution benthic imaging","authors":"M. Sherlock, A. Marouchos, Alan Williams, A. Tyndall","doi":"10.1109/OCEANSAP.2016.7485396","DOIUrl":"https://doi.org/10.1109/OCEANSAP.2016.7485396","url":null,"abstract":"Towed underwater imaging systems are increasingly used for a wide variety of science applications in the deep ocean. These systems augment data collected by physical sampling such as dredging and trawling, but also provide an important sampling alternative where extractive methods are unnecessary or unsuitable - such as in sensitive habitats or for repeated sampling in marine reserves. Specific applications of image-based sampling are to ground-truth habitat maps at scales of kilometers and quantitatively map benthic biodiversity, i.e. along transects with robust statistical properties (straight with constant speed and height off bottom). The opportunities for scientists to study the deep ocean was boosted in 2015 with the arrival of Australia's new custom built research vessel, RV Investigator. Deep water imaging was identified as a critical capability for the new vessel, and the past experience of engineers and scientists at the Commonwealth Scientific and Industrial Research Organization (CSIRO) have been combined to design and develop a system suited to a variety of user groups and applications - specifically to provide a system capable of repeated, rapid deployments to the seabed to depths of 4000 m. The study of the deep ocean is particularly challenging with vessel-towed gear because of the engineering considerations in design of depth rated components and remoteness of the platform from the vessel (typically kilometers). The system is towed by an electro-mechanical fiber optic cable. This allows the imaging system and sensor suite to be monitored and controlled in real time from the ship's science operations room during all phases of a deployment. The platform is equipped with several imaging systems, with options for future expansion. A high resolution DSLR camera paired with a high definition video camera provide the benthic science data. These two cameras are focused on the bottom to give an oblique perspective, with illumination provided by four LED lights. The settings of both the DSLR camera and lighting system can be adjusted in real time. A pair of lasers with known separation is used to scale the field of view of both the video and the digital stills system. To aid in navigation and obstacle avoidance, a forward looking camera is used. In addition to imaging, the system is equipped with a CTD and altimeter, and has the capability to accommodate additional sensors. A USBL beacon permits accurate targeting of particular seabed features.","PeriodicalId":382688,"journal":{"name":"OCEANS 2016 - Shanghai","volume":"52 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131800272","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 dataset to evaluate underwater image restoration methods","authors":"Amanda C. Duarte, Felipe Codevilla, Joel De O Gaya, S. Botelho","doi":"10.1109/OCEANSAP.2016.7485524","DOIUrl":"https://doi.org/10.1109/OCEANSAP.2016.7485524","url":null,"abstract":"Image restoration methods have been made to repair images that have some kind of degradation. Most of these methods are designed to deal with the degradation caused by the over-land effects. However, when the images was captured in underwater environments, there are different properties that can degrade the image in unusual ways. This work aims to evaluate how the popular image restoration methods behaves when applied in underwater images with the presence of turbidity in the water. For this, we propose a dataset where we are able to control the amount of image degradation due to underwater properties on a scenario with 3D objects that represents the seabed characteristics. After that, we evaluate the restoration of these methods and their behavior through the image degradation due to turbidity.","PeriodicalId":382688,"journal":{"name":"OCEANS 2016 - Shanghai","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132218235","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":"Acoustic communication channel model in the under-ice environment","authors":"Shengxing Liu, A. Song, C. Shen","doi":"10.1109/OCEANSAP.2016.7485515","DOIUrl":"https://doi.org/10.1109/OCEANSAP.2016.7485515","url":null,"abstract":"We develop acoustic communication simulation tools that integrate acoustic wave propagation model with acoustic communication algorithms for the under-ice environment. Our acoustic model uses the BELLHOP ray model augmented with multiple ice layers. Assuming a three-layer model, i.e. seawater/ice/air, we derive matrix expressions for the reflection and transmission coefficients of sound incident from seawater to ice. With the obtained reflection and transmission coefficients, we apply the BELLHOP ray tracing method to the under-ice environment. Impacts of sound frequency, incident angle, and thickness of ice on the reflection coefficient are investigated. Transmission loss as well as channel impulse responses versus range are simulated by the modified BELLHOP ray tracing method.","PeriodicalId":382688,"journal":{"name":"OCEANS 2016 - Shanghai","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134317263","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 numerical simulation of oil spill in Jiaozhou Bay","authors":"Cheng Li, Huan Li, Jia Gao, L. Mu, Guosong Wang, Jun Song","doi":"10.1109/OCEANSAP.2016.7485641","DOIUrl":"https://doi.org/10.1109/OCEANSAP.2016.7485641","url":null,"abstract":"Marine oil spill is an inevitable and undesirable consequence of producing and transporting petroleum, as well as the associated refined products. To reduce oil spill pollution, China has made many great achievements to develop adequate pollution contingency plans for several years. During the oil spill response, it is important to understand the behavior and fate of spilled oil in the forecasting and prediction techniques, ensuring to implement the emergency plans. In this paper, the Integrated and Multi-node Cooperative Marine Oil Spill Forecasting and Warning System is presented. This system, consists of a meteorological forecasting module, a hydrodynamic forecasting module and an oil spill prediction module, was developed for the oil spill prediction in China Seas by National Marine Data and Information Service. Due to the superior performance, IMOSFWS was applied to simulate the major oil spill event occurred in Jiaozhou Bay on November 22, 2013, and provided important and timely oil spill prediction information to China MSA. A high appraisal from China MSA was awarded to the system as a positive feedback.","PeriodicalId":382688,"journal":{"name":"OCEANS 2016 - Shanghai","volume":"105 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134319284","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":"Diving control of an Autonomous Underwater Vehicle using nonlinear H∞ measurement feedback technique","authors":"S. Mahapatra, B. Subudhi, R. Rout","doi":"10.1109/OCEANSAP.2016.7485518","DOIUrl":"https://doi.org/10.1109/OCEANSAP.2016.7485518","url":null,"abstract":"A nonlinear H∞ measurement feedback control algorithm is exploited for the control of Autonomous Underwater Vehicle in the Dive Plane. Here, the control algorithm is designed with the combination of a nonlinear H∞ state feedback law along with a nonlinear observer. The control problem of measurement feedback is formulated in terms of two Hamilton-Jacobi-Isaacs inequality by using the dissipative theory. The solution of the control law is obtained by solving both the inequalities. The controller is intended to track different desired depth values by attenuating the external disturbance. The simulation results are realized using MATLAB/Simulink which suggest that the controller is effective in tracking by ensuring the internal stability and robustness.","PeriodicalId":382688,"journal":{"name":"OCEANS 2016 - Shanghai","volume":"118 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134332654","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":"Neither PAS nor CAS: MIMO","authors":"Y. Pailhas, Y. Pétillot","doi":"10.1109/OCEANSAP.2016.7485394","DOIUrl":"https://doi.org/10.1109/OCEANSAP.2016.7485394","url":null,"abstract":"In this paper, we discuss the PAS (Pulse Active Sonar) and CAS (Continuous Active Sonar) strategies for target detection and tracking. CAS system potentially offer several advantages over traditional PAS systems, mainly in term of probability of detection and/or tracking. With a continuous insonification of the target, CAS can track continuously limiting the data association error inherent to PAS system. Recent works in MIMO (Multiple Input Multiple Output) radar and sonar have bring new solutions for the orthogonal waveform design problem. We present here a modified CDMA (Code Division Multiple Access) waveform adapted to sonar constraints. Using such waveforms offers a mid-way solution between PAS and CAS allowing the user to decrease the PRI (Pulse Repetition Interval) and then increasing the hits on target but not at the cost of sacrificing the full bandwidth.","PeriodicalId":382688,"journal":{"name":"OCEANS 2016 - Shanghai","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134187417","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 background subtraction and three-frame difference to detect moving object from underwater video","authors":"Hongkun Liu, Jialun Dai, Ruchen Wang, Haiyong Zheng, Bing Zheng","doi":"10.1109/OCEANSAP.2016.7485613","DOIUrl":"https://doi.org/10.1109/OCEANSAP.2016.7485613","url":null,"abstract":"Moving object detection is the basis of object tracking and classification in computer vision, which has been applied to underwater robots to execute underwater missions and do marine ecological research. The complicated scene and poor lighting condition in underwater environment usually make moving object detection difficult. To solve above problems and to detect moving object from underwater video, we propose an approach combining background subtraction and three-frame difference. In this method, firstly we detect moving object pixels by background subtraction and three-frame difference perspectively. Next, we perform \"AND\" operation on the results of background subtraction and three-frame difference, background subtraction provides the object information to supplement the incomplete information detected from three-frame difference. Lastly, morphology processing is utilized on the result to remove the noise caused by non-static objects in background. This method shows an effective and reliable performance in detecting moving object from underwater video.","PeriodicalId":382688,"journal":{"name":"OCEANS 2016 - Shanghai","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134506496","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}