Global Oceans 2020: Singapore – U.S. Gulf Coast最新文献

{"title":"A Monte Carlo approach for capturing the uncertainty in sonar performance modelling","authors":"E. M. Bøhler, K. Hjelmervik, Petter Østenstad","doi":"10.1109/IEEECONF38699.2020.9389266","DOIUrl":"https://doi.org/10.1109/IEEECONF38699.2020.9389266","url":null,"abstract":"Sonar performance modelling is an essential part of active sonar operations, as it is used both during planning of the operation as well as assessment of the expected coverage managed during the operation. Conventionally, the acoustic model has been input with a single realisation of the present environment in order to generate 2D coverage plots either as vertical cross sections in a selected direction from the sonar or as horizontal coverage plots encircling the sonar. The impact of envinronmental uncertainty on sonar performance is well known and documented. Errors in the input sound speed may give rise to large errors in the expected sonar performance. Monte Carlo methods are a well known method for capturing this uncertainty. This requires both a multitude of model runs and probability density functions representing the model input instead of single realisations. Here we propose using a fast raytrace model for estimating the sonar performance of a large number of different environmental and target realisations. The model results are then marginalized to collapse all but a few dimensions for efficient and concise presentation of the results for the sonar operator.","PeriodicalId":198531,"journal":{"name":"Global Oceans 2020: Singapore – U.S. Gulf Coast","volume":"12 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115501989","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":"Hybrid Wave Height Estimation from First- and Second-Order Doppler Spectral Peaks of Compact High Frequency Radar","authors":"Yingwei Tian, Zhen Tian, Jiurui Zhao, B. Wen","doi":"10.1109/IEEECONF38699.2020.9389309","DOIUrl":"https://doi.org/10.1109/IEEECONF38699.2020.9389309","url":null,"abstract":"To improve the capability of the compact high frequency (HF) radar in sea surface wave height measurement, three different methods have been investigated during the past years by exploiting either the first-order or the second-order Doppler spectral peaks. Compared with the classical integral inversion framework, the new methods provide a promising potential in wave mapping. However, their limitations in measurable distance and wave height range are still existed. In this paper, through analyzing the difference of the previous three methods, a new hybrid method is proposed by jointly estimating wave height from the first- and second-order Doppler spectral peaks based on the rough sea state level classification. The first- and second-order Doppler spectral peaks are respectively exploited to estimate wave heights of low- and high-waves, which are then fused to obtain the final wave height results. Preliminary experimental results are given to validate the effectiveness of the proposed method.","PeriodicalId":198531,"journal":{"name":"Global Oceans 2020: Singapore – U.S. Gulf Coast","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123044423","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":"Replay-Attack Countermeasures for Underwater Acoustic Networks","authors":"Filippo Campagnaro, Davide Tronchin, Alberto Signori, R. Petroccia, Konstantinos Pelekanakis, P. Paglierani, J. Alves, M. Zorzi","doi":"10.1109/IEEECONF38699.2020.9389259","DOIUrl":"https://doi.org/10.1109/IEEECONF38699.2020.9389259","url":null,"abstract":"Security is an important service of Underwater Acoustic Networks (UANs). In this work, we investigate the impact of four different replay attacks and propose two counteracting methods. The first method is based on the observation of the packet generation timestamp and the second method uses the HASH value of the packet generation timestamp combined with the address of the source node. These two methods are implemented between the routing and Media Access Control (MAC) layers of the DESERT communications protocol stack. Our simulation results show that the proposed countermeasures almost neutralise the attacks for two different network topologies.","PeriodicalId":198531,"journal":{"name":"Global Oceans 2020: Singapore – U.S. Gulf Coast","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121817881","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":"Cabled Community Observatories for Coastal Monitoring - Developing Priorities and Comparing Results","authors":"R. Flagg, Tanner J. Owca, Lucianne M. Marshall, A. Snauffer, J. Bédard, M. Hoeberechts","doi":"10.1109/IEEECONF38699.2020.9389268","DOIUrl":"https://doi.org/10.1109/IEEECONF38699.2020.9389268","url":null,"abstract":"Coastal marine environments are some of the most bio-rich ecosystems on earth, providing food and livelihoods for many coastal community members. Yet, many of these coastal environments are threatened by anthropogenic and climate stressors resulting in the need for robust monitoring to inform current and future environmental stewardship decisions. While traditional oceanographic sampling is typically done from a research vessel, this is often costly and logistically difficult for scientists and coastal communities alike. Ocean Networks Canada (ONC) in partnership with communities along Canada’s western, eastern, and Arctic coasts have continued to advance a number of solutions for long-term marine monitoring. Here, we discuss the development and implementation of seafloor cabled observatories, which collect continuous real-time data intended to help inform government, industry, and communities, and advance the scientific understanding of coastal environments. The strategic placement of these observatories, with collaboration from community partners, allows for high resolution datasets in both significant and remote regions of Canada. Each underwater platform has the potential to house a variety of instruments, which are connected to an underwater cable for real-time data transmission to the surface and which often allows the instruments to be powered from shore. Shore stations provide connectivity to the instruments and also provide an opportunity to host other shore-based instruments that can complement the underwater suite. Since large amounts of data are more easily and efficiently stored and transferred continuously rather than with battery-dependent autonomous systems, these observatory systems are well suited for collecting year-round, high temporal-resolution data. Thisallows for traditional physical oceanographic parameters to reveal environmental changes not only over annual and decadal time scales but also over diurnal (and shorter) time scales. These systems are more efficient at supporting year-round deployments of hydrophones, active acoustic instruments, surface and subsea video cameras, radars, and other high data-density instruments than their autonomous counterparts. Data from ONC’s network of observatories are relayed from shore stations over the internet via fibre, cellular, or satellite connection to the Oceans 2.0 data management system. Oceans 2.0 supports open data access, detailed metadata support, sensor health monitoring, QA/QC of the data, data products, and a wide range of web services. All of these factors together serve to fill several major data and knowledge gaps to better understand our dynamic coastal waters. These community-based platforms have proven to be excellent tools for advancing and supporting ocean literacy and education resources by providing valuable and engaging resources to educators around the world, for all grade levels from primary education to postgraduate studies. They have also been used succe","PeriodicalId":198531,"journal":{"name":"Global Oceans 2020: Singapore – U.S. Gulf Coast","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125242963","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":"On the localization of artificial submarine groundwater discharge sites using a low-cost multi-sensor-platform","authors":"Christoph Tholen, R. Rofallski, L. Nolle, Tarek A. El-Mihoub, I. Parnum, O. Zielinski","doi":"10.1109/IEEECONF38699.2020.9389450","DOIUrl":"https://doi.org/10.1109/IEEECONF38699.2020.9389450","url":null,"abstract":"In this paper, a low-cost, multi-sensor platform designed to investigate the spatial distribution of water quality properties is presented. The platform is based on an off-the-shelf underwater vehicle and various environmental sensors. Its intended application is the detection and mapping of submarine groundwater discharge (SGD), but it could be used for other related applications. In this study, an artificial submarine groundwater discharge (ASGD) was used to test the platform. Before the ASGD was installed, the study area was thoroughly surveyed using the platform developed to establish a baseline. After installation of the ASGD, the area was again thoroughly surveyed with the platform. The spatial and temporal variation in the data collected was used to evaluate the platform and sensors performances, and the usefulness of the different environmental parameters in mapping SGD. Although the experiments performed showed an influence of the ASGD on the measurements, this influence was smaller than expected. Different possible causes for this are discussed.","PeriodicalId":198531,"journal":{"name":"Global Oceans 2020: Singapore – U.S. Gulf Coast","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116643801","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":"Development of a low cost, self-configuring ADCP and integrated deployment and recovery system","authors":"D. Velasco, M. Jørgensen, Anders Nesheim, S. Nylund","doi":"10.1109/IEEECONF38699.2020.9389146","DOIUrl":"https://doi.org/10.1109/IEEECONF38699.2020.9389146","url":null,"abstract":"Here we present the development of a short range (0.5 to 20 m), low cost (< USD 5,000), three-beam, 1 MHz acoustic Doppler current profiler called the Nortek ECO. The system employs a robust wideband velocity measurement technique where the only required user inputs are: 1) when deployment should start, 2) how often to sample, and 3) what is the water type. The hardware is highly portable, measuring only 130 mm tall by 85 mm in diameter and weighing 1.0 kg in air. It communicates externally with Bluetooth Low Energy technology, and is powered by an embedded smart Li-Ion battery that is charged by induction. Three independent activation methods are implemented, including Near-Field Communication, and all communication controlled via a platform-independent Progressive Web App. Coupled with the ADCP is a deployment and recovery system allowing for single-person operation at depths up to 50 m. Discussion of the system concept and design are presented, including sample data.","PeriodicalId":198531,"journal":{"name":"Global Oceans 2020: Singapore – U.S. Gulf Coast","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117111355","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":"Towards Bayesian Ocean Physical- Biogeochemical- Acidification Prediction and Learning Systems for Massachusetts Bay","authors":"P. Haley, A. Gupta, C. Mirabito, Pierre FJ Lermusiaux","doi":"10.1109/IEEECONF38699.2020.9389210","DOIUrl":"https://doi.org/10.1109/IEEECONF38699.2020.9389210","url":null,"abstract":"Better quantitative understanding and accurate data-assimilative predictions of the three-dimensional and time-dependent ocean acidification (OA) processes in coastal regions is urgently needed for the protection and sustainable utilization of ocean resources. In this paper, we extend and showcase the use of our MIT-MSEAS systems for high-resolution coupled physical-biogeochemical-acidification simulations and Bayesian learning of OA models in Massachusetts Bay, starting with simple empirical and equilibrium OA models. Simulations are shown to have reasonable skill when compared to available in situ and remote data. The impacts of wind forcing, internal tides, and solitary waves on water transports and mixing, and OA fields, are explored. Strong wind events are shown to reset circulations and the OA state in the Bay. Internal tides increase vertical mixing of waters in the shallow regions. Solitary waves propagating off Stellwagen Bank coupled with lateral turbulent mixing provide a pathway for exchange of surface and deep waters. Both of these effects are shown to impact biological activity and OA. A mechanism for the creation of multiple subsurface chlorophyll maxima is presented, involving wind-induced upwelling, internal tides, and advection of near surface fields. Due to the measurement sparsity and limited understanding of complex OA processes, the state variables and parameterizations of OA models are very uncertain. We thus present a proof-of-concept study to simultaneously learn and estimate the OA state variables and model parameterizations from sparse observations using our novel dynamics-based Bayesian learning framework for high-dimensional and multi-disciplinary estimation. Results are found to be encouraging for more realistic OA model learning.","PeriodicalId":198531,"journal":{"name":"Global Oceans 2020: Singapore – U.S. Gulf Coast","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127378742","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 development of Remotely Operated Unmanned Surface Vehicle for Oceanographic studies","authors":"T. Vikranth, R. Srinivasan, S.S.V.S Rama Krishna, K. Rajesh","doi":"10.1109/IEEECONF38699.2020.9389023","DOIUrl":"https://doi.org/10.1109/IEEECONF38699.2020.9389023","url":null,"abstract":"Autonomous & Remotely operated unmanned surface vehicles in oceanographic studies have been increasing in recent years. Not all the surface vehicle platforms are suitable for all oceanographic application. The geographical area of oceanographic study plays a key role in the designing of the surface vehicle platform. In this study, a Remotely Operated Unmanned Surface Vehicle (ROUSV) is designed for oceanographic studies such as air-sea interaction at the coastal area and spatial & temporal variation of salinity and surface water temperature in the estuary from estuary head to estuary mouth. A suitable ROUSV is designed, simulated, fabricated, tested, and collected the oceanographic data at the study area successfully. Air-sea flux estimation study is done by ROUSV at Coral Beach, Vaisakhi Bay, Mangamaripeta, Visakhapatnam coastal area, Andhra Pradesh, East coast of India 17.7246404N 83.3286702E Bay of Bengal (BOB) sea. Collected oceanographic parameters by the ROUSV are Sea Surface Temperature (SST), air temperature, ambient humidity, this data utilized to estimate the sensible and latent heat flux rate by indirect calculation of flux by means of the bulk formula method. Observed Sea Surface Temperature ranges from 24.19°C to 23.31°C, ambient air temperature varies in between 28.9°C to 23.33°C ambient humidity ranges from 61.83% to 61.60%. Calculated sensible heat flux various in between 14.72 w/m2 to −1.23w/m2 and Latent heat flux various between 56.96 w/m2to 22.37w/m2 over East Indian Coastal Current on 06/02/2019 from 8:30am IST to 9:12am IST. Spatial & temporal variation of salinity and surface water temperature data collected from estuary head to estuary mouth conducted at Bhavanapadu estuary (18.5616 N 84.3494 E) at North East coast of Andhra Pradesh, adjoining the Bay of Bengal Sea. A portable SEABIRD CTD 37SM_RS232_041 is attached to the platform and operated in the estuary from estuary head to estuary mouth on 25/03/2020 at 11:38am IST, it is noticed that the surface water temperature is increasing from estuary mouth to estuary head from 28.1°C to 28.7°C, the surface water salinity is also increasing from the estuary mouth to the estuary head 33.3psu to 32.3psu.","PeriodicalId":198531,"journal":{"name":"Global Oceans 2020: Singapore – U.S. Gulf Coast","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123413228","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":"Preliminary Assessment of Wave Energy for Xisha Islands in the South China Sea","authors":"Yizhou Fang, Yang Bai, Song Zhang, Erhu Hou, He Wu","doi":"10.1109/IEEECONF38699.2020.9389284","DOIUrl":"https://doi.org/10.1109/IEEECONF38699.2020.9389284","url":null,"abstract":"The exploitation of wave energy will benefit remote islands considering environmental, social, and economic aspects. Located more than 250 kilometres off the Hainan Island, Xisha Islands is an archipelago in the South China Sea (SCS) that is yet to be grid-connected. Previous studies suggested the SCS has vast and untapped wave energy. Here, high-resolution wave hindcast generated by a nesting SWAN model is used for the assessment of wave energy resource in Xisha Islands. The result of the spatial-temporal analysis highlights the seasonal variability in wave energy, as the mean wave power density ranging from 2 to 12 kW/m between summer and winter. Spatial variation of wave energy majorly caused by depth-induced wave breaking, and blockage effect of islands and reefs. Available wave conditions for the operation of WECs are also discussed, showing that wave energy can provide stable and sustainable energy to islands in Xisha.","PeriodicalId":198531,"journal":{"name":"Global Oceans 2020: Singapore – U.S. Gulf Coast","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123423170","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":"The PRM-A* Path Planning Algorithm For UUVs: An Application To Navy Mission Planning","authors":"Mohammad Imran Chowdhury, D. Schwartz","doi":"10.1109/IEEECONF38699.2020.9388987","DOIUrl":"https://doi.org/10.1109/IEEECONF38699.2020.9388987","url":null,"abstract":"This paper presents a novel path planning algorithm for unmanned underwater vehicles (UUVs) that arises by combining two well-known algorithms in such a way as to exploit their respective advantages while mitigating their deficiencies. The two algorithms are A-star (A*) and Probabilistic Road Map (PRM). The operational environment is given as a portion of open sea interspersed with various obstacles. The free space is the portion not occupied by obstacles. A* employs heuristic search to explore the free space for a path from the start to the goal. This algorithm always returns the shortest (optimal cost) path. A drawback is that the path sometimes runs dangerously close to an obstacle. In addition, the computed path can have sharp turns that are difficult for the UUV to negotiate. PRM starts with a random sampling of the points in the free space. Once some predetermined number of such points are chosen, each point is paired with some of it's free space neighbors, and these pairs are recorded in what is called a road map. Then Dijkstra's algorithm is applied to the road map using nearest neighbor information to find a path from the start node to the goal. This has the advantage that the resulting path is smooth (no sharp turns) and stays safely away from the obstacles. It has the drawback that the path is not optimal; it can be much longer than necessary. The idea presented in this paper is to first run both A* and PRM on the given operational environment. Then take the region bounded by these two lines as a new (smaller) operational environment, and rerun PRM. This produces a new path that more closely approximates the A* path while at the same time is smooth and, with proper monitoring, is assured to keep a safe distance from the obstacles. This procedure can be repeated as many times as desired, each time producing a better approximation of the optimal A* path. While the focus here has been on UUVs, the same approach can be applied for unmanned surface vehicles (USVs),","PeriodicalId":198531,"journal":{"name":"Global Oceans 2020: Singapore – U.S. Gulf Coast","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125551188","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}