OCEANS 2019 MTS/IEEE SEATTLE最新文献

{"title":"Bayesian Iterative Channel Estimation for Multiple-Input Multiple-Output Underwater Acoustic Communications","authors":"Xiangzhao Qin, Fengzhong Qu, Y. R. Zheng","doi":"10.23919/OCEANS40490.2019.8962661","DOIUrl":"https://doi.org/10.23919/OCEANS40490.2019.8962661","url":null,"abstract":"This paper derives a MIMO system model that considers the spatial correlation and sparse nature of MIMO UWA channels. Accordingly, we proposes a improved sparse Bayesian learning (I-SBL) algorithm for joint estimating the channel coefficients, residual noise and channel covariance power via the robust expectation maximum (EM) update algorithm. By employing the a priori noise power and the second-order channel covariance matrix acquired from the training sequence, the proposed I-SBL channel estimator achieves faster convergence and easier hyperparameter control than that of the conventional Bayesian algorithm while enjoying better estimation accuracy than the classic channel estimation algorithms. Experimental results have verified that the proposed scheme outperforms the minimum mean square error (MMSE), conventional Bayesian, orthogonal matching pursuit (OMP) and adaptive improved least mean squares (IPNLMS) channel estimators in terms of the channel sparseness control and BER performance.","PeriodicalId":208102,"journal":{"name":"OCEANS 2019 MTS/IEEE SEATTLE","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130111027","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":"Model-Based Sediment Characterization Using Multibeam Angular Backscatter Data","authors":"Haiyan Ni, Wenbo Wang, Qunyan Ren, Licheng Lu, Jinrong Wu, Li Ma","doi":"10.23919/OCEANS40490.2019.8962831","DOIUrl":"https://doi.org/10.23919/OCEANS40490.2019.8962831","url":null,"abstract":"This paper discusses a model-based approach to sediment characterization using multibeam backscatter data collected offshore from Qingdao, China in 2018. In this experiment, the NORBIT wideband multibeam sonar was utilized to collect backscatter data, the angular response curves of which reflect sediment-type differences. For the synthetic analysis of experimental data, a high-frequency backscatter model based on small-slope approximation and volume-scattering theory was adapted to simulate the variation of the backscatter strength with the incident angle. Afterward, these generated model replicas were matched with experimental backscatter data using a simulated annealing optimization algorithm to estimate sediment parameters, such as sediment–water sound-speed ratio, density ratio, roughness spectral parameters, volume-scattering strength, and acoustics attenuation. The preliminary inversion results are basically consistent with the experimental data on sediment distribution and texture.","PeriodicalId":208102,"journal":{"name":"OCEANS 2019 MTS/IEEE SEATTLE","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130270114","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 Auto-tuning of Kalman Filters for Underwater Gliders based on Consistency Metrics","authors":"Levi Cai, Burak Boyacioglu, Sarah E. Webster, Lora van Uffelen, K. Morgansen","doi":"10.23919/OCEANS40490.2019.8962573","DOIUrl":"https://doi.org/10.23919/OCEANS40490.2019.8962573","url":null,"abstract":"Underwater gliders are often used to perform in-situ measurements of oceanographic systems. In particular, there have been a number of recent efforts to use their state estimation capabilities in order to infer physical oceanographic process dynamics, such as modeling currents and eddies. Such inference requires that the dead-reckoning systems used on the vehicles, typically hand-tuned Extended Kalman Filters (EKFs), to be tuned consistently, which can be tedious and burdensome, especially across large numbers of trials. In this work, we describe a method to automatically tune state estimation hyper-parameters used in underwater glider EKFs, that does not require ground truth estimates. This automation is achieved by taking advantage of the normalized innovation squared (NIS) metric, which can be used inside of the objective function of various optimization methods. In this paper, we demonstrate its validity in simulated environments and provide initial results for its use on fielded glider data.","PeriodicalId":208102,"journal":{"name":"OCEANS 2019 MTS/IEEE SEATTLE","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129660644","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":"How Modern Multibeam Surveys Can Dramatically Increase Our Understanding of the Seafloor and Waters Above to Support the United Nations Decade of Ocean Science for Sustainable Development","authors":"D. Millar, G. Mitchell, K. Brumley","doi":"10.23919/OCEANS40490.2019.8962596","DOIUrl":"https://doi.org/10.23919/OCEANS40490.2019.8962596","url":null,"abstract":"Multibeam echosounder (MBES) technology has been constantly evolving since its commercial introduction in the late 1970s. The early systems were large and designed to efficiently acquire bathymetric data in deep water. As the underlying sonar technologies improved and computing power increased, systems became smaller and capable of operating on a wider range of vessels over a broader range of depths. Modern deep seafloor exploration, and our present understanding of the geomorphological and biophysical processes that shape it, are closely linked to advances in multibeam echosounder technology. Low- to mid-frequency (12–30 kHz) acoustic waves generated by MBES sonars can penetrate kilometers of water column and remotely measure the deep seafloor and shallow subsurface. Reflectivity measurements of the seafloor and water column can also be extracted from MBES datasets, but until the last decade of the 20th century, only the bathymetric swath data was being utilized. In the 1990s, scientists began taking advantage of the multibeam acoustic wave's reflected energy, or backscatter, to interpret information on seafloor geometry (slope), physical characteristics (hardness and roughness), and intrinsic properties, such as composition, surficial and volumetric scattering. Analyzing the geophysical signature of reflected acoustic beams has proven an effective quantitative and qualitative tool to remotely characterize the lithologic composition and geologic nature of the seafloor. Analyzing seafloor backscatter and most recently, backscatter intensities in the water column, has been used for a wide range of applications, including fisheries research, marine biomass assessment, benthic habitat mapping, geological classification, subsea engineering and geohazard mitigation, and hydrocarbon seep studies. This presentation will briefly look at the evolution of MBES technology before focusing on how modern MBES surveys, using the latest generation technology, can deliver a comprehensive characterization of the seafloor and the waters above, as opposed to bathymetry data alone. With The Nippon Foundation-GEBCO Seabed 2030 Project now underway, and planning for the United Nations (UN) Decade of Ocean Science for Sustainable Development having recently commenced, modern MBES technology will play a critical role in bridging ocean bathymetry and ocean observation to improve our understanding of the ocean, its seafloor and its processes. One of the key R&D priorities of the Decade is a comprehensive map (digital atlas) of the ocean. Modern multibeam surveys will support not only bathymetric mapping, but also physical, biological, chemical, geologic, ecosystem, cultural and resource mapping of the world's oceans. Such an approach can feed both Seabed 2030 and the Decade to deliver, as the UN has so eloquently stated, “the ocean we want for the future we need.”","PeriodicalId":208102,"journal":{"name":"OCEANS 2019 MTS/IEEE SEATTLE","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131303447","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":"Frequency Invariant Beamformers for Underwater Sound","authors":"E. Stytsenko, M. Poletti, M. Meijer, N. Scott","doi":"10.23919/OCEANS40490.2019.8962713","DOIUrl":"https://doi.org/10.23919/OCEANS40490.2019.8962713","url":null,"abstract":"The increasingly widespread use of broadband acoustic signals for underwater communications, sonars for survey work and fisheries research incentivises the design of beamformers with frequency-invariant beampatterns to minimise angular variations of the signal spectral content and angular width of the beam with frequency. In this paper, we present a technique for frequency invariant beam generation using a delay and sum procedures for linear and 2D arrays with half-wavelength element spacing at the highest frequency of interest and a transformation of this approach into a 3D array topology.","PeriodicalId":208102,"journal":{"name":"OCEANS 2019 MTS/IEEE SEATTLE","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128863447","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":"Field testing and performance evaluation of the Long-term Acoustic Real-Time Sensor for Polar Areas (LARA)","authors":"H. Matsumoto, T. Nakamura, J. Haxel, B. Kahn, L. Roche, R. Dziak, A. Turpin, J. Childress, K. Sexton, H. Klinck","doi":"10.23919/OCEANS40490.2019.8962602","DOIUrl":"https://doi.org/10.23919/OCEANS40490.2019.8962602","url":null,"abstract":"In the Arctic, in-situ measurement of the upper water column properties (e.g., salinity and temperature) has been a challenge because of the seasonal sea ice coverage. A Long-term Acoustic Real-Time Sensor for Polar Areas (LARA) was developed, field-tested in the shallow water off Oregon and its performance evaluated. The LARA utilizes a commercially available underwater profiler winch from NiGK, conductivity-temperature-depth (CTD) sensors, and a passive acoustic monitoring (PAM) systems. The sensor section consists of two modules: 1) a satellite antenna with a temperature and depth sensor (TD) and 2) a sensor buoy with a controller, a CTD, and a PAM. Using the two vertically separated temperature and pressure sensors, it is capable of detecting the presence of sea ice by sensing the oceanographic conditions in the upper water column. In addition, using the acoustic sensors, (1) surface wind speed can be estimated from the ambient noise level and (2) enable monitoring of marine mammal calling activity. The winch can be fully controllable from the sensor buoy by acoustic commands. It is capable of aborting an ascent in case sea ice coverage or a high sea state was detected. Although the sea ice detection algorithm could not be tested in Oregon waters, the LARA successfully repeated 94 profiles and transmitted CTD and acoustic detections data via satellite. The wind speed estimates by the PAM were in good agreement with the nearby buoy data. The PAM recorded various biological signals from 10 Hz to 60 kHz including vocalizations of fin, humpback, sperm whales and calls of Pacific white-sided dolphins. The system is capable of repeating 365 profiles or one profile per day for 1 year making it suitable for collecting high-resolution water column data in the extreme weather and water conditions of the Arctic.","PeriodicalId":208102,"journal":{"name":"OCEANS 2019 MTS/IEEE SEATTLE","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128908972","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 Oil Under Ice: An Acoustic Reverberation Method","authors":"Patrick L. Kelley, Drake B. Lafleur, Jacob M. Brendly, R. Hildebrand, D. C. Baumann, Edoardo I. Sarda","doi":"10.23919/OCEANS40490.2019.8962665","DOIUrl":"https://doi.org/10.23919/OCEANS40490.2019.8962665","url":null,"abstract":"Through new exploration and aging infrastructure, there is an ever-increasing risk of oil spills or leaks into natural bodies of water, but presently there is no low-cost method to actively monitor for such spills under ice cover, particularly not any method giving rapid coverage of a large area. Therefore, a method based on acoustic reverberation time under the ice was investigated. A broadband, impulsive acoustic source generating a frequency band of 10–90 kHz was used in a water tank with a layer of naturally-grown ice for a scaled feasibility study of this method; this band provided appropriately short wavelengths, scaled for the small tank environment. Reflections from the tank walls were minimized, and a diffuse environment within the tank allowed for extraction of a reverberation time with a hydrophone. Results show an oil presence changed the reverberation time as compared to an oil-free ice layer across all diffuse frequency bands.","PeriodicalId":208102,"journal":{"name":"OCEANS 2019 MTS/IEEE SEATTLE","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116001585","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":"Three-Dimensional, Low-Resolution Desktop Geomorphometric Modelling of the Arctic Ocean Floor","authors":"I. Florinsky, S. Filippov","doi":"10.23919/OCEANS40490.2019.8962845","DOIUrl":"https://doi.org/10.23919/OCEANS40490.2019.8962845","url":null,"abstract":"Submarine topography is one of the main factors determining the course and direction of processes occurring at the boundary between lithosphere and hydrosphere. We present results of the first phase of a project to create a system for three-dimensional (3D) geomorphometric modelling of the Arctic Ocean floor. In this phase, we developed a test, desktop version of the system. We utilized a small, 10-km gridded digital elevation model (DEM) extracted from the International Bathymetric Chart of the Arctic Ocean (IBCAO) version 3.0. From the DEM, we derived digital models of several morphometric variables: horizontal, vertical, minimal, and maximal curvatures, as well as catchment and dispersive areas. To construct and visualize 3D morphometric models of the territory, we applied an original approach for 3D terrain modelling in the environment of the Blender package, free and open-source software. We present a series of 3D morphometric models with perspective views from the Atlantic, Eurasia, the Pacific, and North America. The experiment showed that the approach is efficient and can be used for creating next, desktop and web versions of the system for visualizing morphometric models with higher resolutions.","PeriodicalId":208102,"journal":{"name":"OCEANS 2019 MTS/IEEE SEATTLE","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122485586","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":"Long-Endurance Green Energy Autonomous Surface Vehicle Control Architecture","authors":"A. Dallolio, B. Agdal, A. Zolich, J. A. Alfredsen, T. Johansen","doi":"10.23919/OCEANS40490.2019.8962768","DOIUrl":"https://doi.org/10.23919/OCEANS40490.2019.8962768","url":null,"abstract":"This paper presents the system design and architecture of a wave-powered Autonomous Surface Vehicle (ASV). The proposed solution complies with the self-powering nature of the vehicle, ensuring long-duration operations in the open ocean. In our field-tested concept, the vehicle is equipped with the instruments and capabilities to deal with the environmental uncertainties, while serving as an in-situ data provider for oceanographers and biologists. Robustness to mission failure and a high degree of redundancy are achieved by allocating computational efforts and responsibilities to independent subsystems. A three-layered system subdivision facilitates the implementation of several capabilities involving solar energy harvesting, storage and distribution, radio communication, autonomous navigation, AIS-based collision avoidance and onboard autonomy to supervise both the mission execution and the scientific payload employment.","PeriodicalId":208102,"journal":{"name":"OCEANS 2019 MTS/IEEE SEATTLE","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122513726","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 Backstepping Approach for Networked Control of a Multi-Vehicle Team of Autonomous Under-Ice Profilers","authors":"Ian Buckley, M. West, M. Egerstedt, C. Walker","doi":"10.23919/OCEANS40490.2019.8962667","DOIUrl":"https://doi.org/10.23919/OCEANS40490.2019.8962667","url":null,"abstract":"Recent advances in the capabilities of autonomous underwater vehicles suggest their growing utility in support of oceanographic inquiry. Towards developing autonomous systems to aid in monitoring and exploration of the polar, under-ice environment, this paper examines multi-vehicle teams consisting of autonomous profilers, a class of low-cost autonomous underwater vehicles that can only actuate their depth. Existing research on the under-ice environment documents the existence of depth-dependent ocean currents, which can be opportunistically leveraged to coordinate the motion of a team of autonomous profilers. As such, this paper proposes a backstepping control strategy that enables teams of autonomous profilers to execute established networked control algorithms; the backstepping controllers are examined through simulation and deployment on a team of differential-drive robots.","PeriodicalId":208102,"journal":{"name":"OCEANS 2019 MTS/IEEE SEATTLE","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116339959","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}