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A Machine Learning, Multi-Band Spectral Reflectance Clustering Approach for Examining Physical Transformations in Landfast Sea Ice Environments Affected by Spring Freshets

SSRN

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SSRN 2025年

作者： Catipovic, Luka Laney, Samuel R. Woods Hole Oceanographic Institution Woods HoleMA United States The MIT-WHOI Joint Program in Oceanography/Applied Ocean Science and Engineering Cambridge and Woods Hole MA United States City College of New York New YorkNY United States

Highlights• ML algorithms can classify water and sea ice characteristics in the coastal Arctic.• Spring freshet runoff over sea ice is optically distinct from surface melt ponds.• Time-series analyses of satellite ima... 详细信息

关键词： Sea ice

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THE RELATIONSHIP BETWEEN VERTICAL, DIAPYCNAL, AND ISOPYCNIC VELOCITY AND MIXING IN THE OCEAN GENERAL-CIRCULATION

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JOURNAL OF PHYSICAL OCEANOGRAPHY 1986年第1期16卷 167-174页

作者： BENNETT, SL MIT-WHOI Joint Program Woods Hole Oceanographic Institution Woods Hole 02543 MA United States

On ocean general circulation scales, vertical velocitywis extremely small, O(10−5) smaller than the horizontal velocity in scale. Nevertheless, it is of great importance to advective–diffusive and vorticity balances. In order to better understand the relationship between the cross-isopycnal (diapycnal) velocity, the mixing, andw, in a nonideal ocean in which some mixing and density sources are present, the velocity vector is decomposed into isopycnal and diapycnal components. Applying this decomposition to the exact continuity (mass conservation) equation, it is shown that while the diapycnal divergence is in principle the first correction to the isopycnal divergence for general circulation scales, the observational uncertainties in the isopycnal velocity are large enough that the diapycnal divergence cannot in practice be determined. Using these results, the horizontally averaged near-vertical (diapycnal) velocity computed by Wunsch et al. in a model of the South Pacific (28–43°S) is reconsidered. It is shown that the calculation of diapycnal velocity from isopycnal mass convergence is not consistent with uncertainties in the isopycnal velocity and that the implied mixing cannot be accounted for with simple diffusion models and salt-fingering alone.

关键词： Velocity

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Distributed Certifiably Correct Range-Aided SLAM

arXiv

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arXiv 2025年

作者： Thoms, Alexander Papalia, Alan Velasquez, Jared Rosen, David M. Narasimhan, Sriram Sensing and Robotics for Infrastructure Laboratory University of California Los Angeles Los Angeles United States The Massachusetts Institute of Technology The MIT-WHOI Joint Program in Oceanography/Applied Ocean Science & Engineering Woods Hole CambridgeMA United States Robust Autonomy Lab Northeastern University BostonMA United States

Reliable simultaneous localization and mapping (SLAM) algorithms are necessary for safety-critical autonomous navigation. In the communication-constrained multi-agent setting, navigation systems increasingly use point-to-point range sensors as they afford measurements with low bandwidth requirements and known data association. The state estimation problem for these systems takes the form of range-aided (RA) SLAM. However, distributed algorithms for solving the RA-SLAM problem lack formal guarantees on the quality of the returned estimate. To this end, we present the first distributed algorithm for RA-SLAM that can efficiently recover certifiably globally optimal solutions. Our algorithm, distributed certifiably correct RA-SLAM (DCORA), achieves this via the Riemannian Staircase method, where computational procedures developed for distributed certifiably correct pose graph optimization are generalized to the RA-SLAM problem. We demonstrate DCORA’s efficacy on real-world multi-agent datasets by achieving absolute trajectory errors comparable to those of a state-of-the-art centralized certifiably correct RA-SLAM algorithm. Additionally, we perform a parametric study on the structure of the RA-SLAM problem using synthetic data, revealing how common parameters affect DCORA’s performance. Copyright © 2025, The Authors. All rights reserved.

关键词： Navigation systems

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EVIDENCE FOR CONTROL OF ABYSSAL AGGLUTINATED FORAMINIFERAL COMMUNITY STRUCTURE BY SUBSTRATE DISTURBANCE - RESULTS FROM THE HEBBLE AREA

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MARINE GEOLOGY 1985年第1-4期66卷 113-131页

作者： KAMINSKI, MA WHOI/MIT Joint Program in Oceanography Woods Hole Oceanographic Institution Woods Hole MA 02543 U.S.A.

Deep-sea agglutinated foraminifera have been quantitatively examined from 28 coretop samples from seven box cores collected in June, 1983, at the HEBBLE (High Energy Benthic Boundary Layer Experiment) Site (40°27′N, 62°20′W, 4815–4825 m depth) and HEBBLE Shallow Site (40°53′N, 63°44′W, 4185 m depth) on the Nova Scotian continental rise. Samples from the relatively tranquil HEBBLE Shallow Site can be distinguished from the HEBBLE Site on the basis of their microfauna. A Q-mode VARIMAX factor analysis of species-frequency data delineates three major faunal assemblages: 1. (1) A faunal assemblage from the HEBBLE Site dominated by Ammobaculties sp. cf. A. americanus. This assemblage exhibits lowest species diversity (suggesting a disturbed community) and strongly associated with box cores containing fine-grained, laminated sediments. 2. (2) An assemblage associated with box cores from the HEBBLE Meadow dominated by Saccammina tubulata, Psammosphaera sp., cf. P. fusca, a coarsely grained species of Psammosphaera and Reophax sp. 1. 3. (3) A fauna occurring at the HEBBLE Shallow Site, dominated by Hormosinella distans, with Reophax bacillaris and Ammobaculites agglutinans unique to the assemblage. This fauna displays a higher ratio of calcareous to agglutinated species, significantly higher species diversity, lower variability and a greater proportion of hormosinids and species utilizing finer grains than samples from the HEBBLE Site, which is interpreted as reflecting environmental stability. Marked heterogeneity exists among agglutinated foraminiferal assemblages within box cores. At the HEBBLE Meadow, within-box-core faunal variability exceeds between-box-core variability, suggesting that environmental factors influencing the distribution of species are patchy on a scale of approximately 40 cm.

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Corrigendum to “Biochemical implications of the Bottom Boundary Layer Detachment at the Mid-Atlantic Bight shelf-break front” [Continent. Shelf Res. 286 (2025) 105408]

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Continental Shelf Research 2025年 288卷

作者： Serena Negroni Dennis J. McGillicuddy Glen G. Gawarkiewicz Paolo Oddo Nadia Pinardi Department of Physics and Astronomy (DIFA) University of Bologna Bologna 40126 Italy MIT/WHOI Joint Program in Oceanography/Applied Ocean Sciences and Engineering Woods Hole 02543 MA USA Woods Hole Oceanographic Institution Woods Hole 02543 MA USA

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Soft-Adaptive Turbo Equalization: Using Soft Information in Adaptation

Soft-Adaptive Turbo Equalization: Using Soft Information in ...

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46th Asilomar Conference on Signals, Systems and Computers

作者： Yellepeddi, Atulya Preisig, James C. Electrical Engineering/Applied Ocean Science and Engineering MIT-WHOI Joint Program USA

ISBN: (纸本)9781467350518

Turbo equalizers have been exploited for underwater wireless communication due to their excellent practical performance. As the equalizer is adaptive, it is possible to take advantage of the soft information available from the decoder in the adaptation process. In this paper, we consider a method to do this and compare it with the use of soft information in feedback, which is a method that has been considered in the past. Data from the KAM11 experiment demonstrates that using soft information in adaptation can improve performance over using it only in feedback. We also consider combining these different approaches and how this affects performance.

关键词： adaptive equalisers marine communication turbo codes

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Coherent source direction estimation for three-row bathymetric sidescan sonars

Coherent source direction estimation for three-row bathymetr...

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Proceedings of the OCEANS '99 MTS/IEEE - Riding the Crest into the 21st Century

作者： Xu, Wen Stewart, W.Kenneth MIT/WHOI Joint Program in Applied Ocean Physics and Engineering Cambridge United States

In the context of three-row bathymetric sidescan sonars, a coherent source direction estimator (CSDE) is proposed to resolve two sources from different direction. This method is compared with the ESPRIT-based approach using different sonar models. The simulations show that CSDE works very well for highly coherent sources and at the signal-to-noise ratio above 10dB while the ESPRIT-based method is quite robust for the incoherent source signal model. In addition, CSDE gives the source time series estimation on the basis of the direction estimation as well.

关键词： Sonar

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Development of a six-degree of freedom simulation model for the REMUS autonomous underwater vehicle

Development of a six-degree of freedom simulation model for ...

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OCEANS

作者： T. Prestero MIT/WHOI Joint Program in Oceanographic Engineering USA

Describes the development and verification of a six degree of freedom, non-linear simulation model for the REMUS AUV, the first such model for this platform. In this model, the external forces and moments resulting from hydrostatics, hydrodynamic lift and drag, added mass, and the control inputs of the vehicle propeller and fins are all defined in terms of vehicle coefficients. The paper briefly describes the derivation of these coefficients. The equations determining the coefficients, as well as those describing the vehicle rigid-body dynamics, are left in non-linear form to better simulate the inherently non-linear behavior of the vehicle. Simulation of the vehicle motion is achieved through numeric integration of the equations of motion. The simulator output is then verified against vehicle dynamics data collected in experiments performed at sea. The simulator is shown to accurately model the motion of the vehicle. The paper concludes with recommendations for future model validation experiments.

关键词： Underwater vehicles Vehicle dynamics Remotely operated vehicles Propellers Nonlinear equations Marine vehicles Hydrodynamics Automotive engineering Life testing Costs

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oceanographic pursuit: Networked control of multiple vehicles tracking dynamic ocean features

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Methods in Oceanography 2014年 10卷 21-43页

作者： Reed, Brooks Hover, Franz Massachusetts Institute of Technology Department of Mechanical Engineering Cambridge 02139 MA United States MIT-WHOI Joint Program Woods Hole Oceanographic Institution Woods Hole MA United States

We present an integrated framework for joint estimation and pursuit of dynamic features in the ocean, over large spatial scales and with multiple collaborating vehicles relying on limited communications. Our approach uses ocean model predictions to design closed-loop networked control at short time scales, and the primary innovation is to represent model uncertainty via a projection of ensemble forecasts into local linearized vehicle coordinates. Based on this projection, we identify a stochastic linear time-invariant model for estimation and control design. The methodology accurately decomposes spatial and temporal variations, exploits coupling between sites along the feature, and allows for advanced methods in communication-constrained control. Simulations with three example datasets successfully demonstrate the proof-of-concept. © 2014 The Authors.

关键词： Autonomous underwater vehicles Collaborative control Ensemble forecasts Feature tracking Linearization System identification

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Tracking Ocean Fronts with Multiple Vehicles and Mixed Communication Losses

Tracking Ocean Fronts with Multiple Vehicles and Mixed Commu...

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IEEE/RSJ International Conference on Intelligent Robots and Systems

作者： Brooks L. Reed Franz S. Hover the MIT/WHOI Joint Program in Oceanographic Engineering MIT Department of Mechanical Engineering

ISBN: (纸本)9781467363563

We make two contributions toward integrated monitoring over large spatial scales, with multiple collaborating vehicles. Our focus is dynamic ocean features such as fronts and plumes. To support strong networked-control designs, we first develop a clean linear time-invariant framework for tracking features, that directly couples the global structure of the process to vehicle positioning. To address the packet loss inherent in underwater acoustic communications, we then extend the synthesis technique of Imer et al. [1] to the case where measurements and control commands suffer loss with differing statistics among the multiple channels. Simulations show that the integrated feedback system achieves good performance in front tracking.

关键词： Tracking Ocean Fronts Multiple Vehicles Mixed Communication Losses

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