English
Related papers

Related papers: Convergence analysis of a variational data assimil…

200 papers

Marine biogeochemistry models are critical for forecasting, as well as estimating ecosystem responses to climate change and human activities. Data assimilation (DA) improves these models by aligning them with real-world observations, but…

Atmospheric and Oceanic Physics · Physics 2025-04-08 Ieuan Higgs , Ross Bannister , Jozef Skákala , Alberto Carrassi , Stefano Ciavatta

We study the flow of water waves over bathymetry that varies periodically along one direction. We derive a linearized, homogenized model and show that the periodic bathymetry induces an effective dispersion, distinct from the dispersion…

Fluid Dynamics · Physics 2021-07-01 Manuel Quezada de Luna , David I. Ketcheson

We show that modifying a Bayesian data assimilation scheme by incorporating kinematically-consistent displacement corrections produces a scheme that is demonstrably better at estimating partially observed state vectors in a setting where…

Data Analysis, Statistics and Probability · Physics 2016-12-06 W. Steven Rosenthal , Shankar C. Venkataramani , Arthur J. Mariano , Juan M. Restrepo

This paper presents a novel centralized, variational data assimilation approach for calibrating transient dynamic models in electrical power systems, focusing on load model parameters. With the increasing importance of inverter-based…

Optimization and Control · Mathematics 2023-11-15 Ahmed Attia , D. Adrian Maldonado , Emil Constantinescu , Mihai Anitescu

It is a common practice to exploit pyramidal feature representation to tackle the problem of scale variation in object instances. However, most of them still predict the objects in a certain range of scales based solely or mainly on a…

Computer Vision and Pattern Recognition · Computer Science 2020-12-10 Zehui Gong , Dong Li

One of the primary goals of coastal water quality monitoring is to characterize spatial variation. Generally, this monitoring takes place at a limited number of fixed sampling points. The alternative sampling methodology explored in this…

Applications · Statistics 2015-04-07 Joseph Stachelek , Christopher J. Madden

Data assimilation (DA) is widely used to combine physical knowledge and observations. It is nowadays commonly used in geosciences to perform parametric calibration. In a context of climate change, old calibrations can not necessarily be…

Machine Learning · Statistics 2021-06-23 Rem-Sophia Mouradi , Cédric Goeury , Olivier Thual , Fabrice Zaoui , Pablo Tassi

Dataset condensation aims to synthesize datasets with a few representative samples that can effectively represent the original datasets. This enables efficient training and produces models with performance close to those trained on the…

Machine Learning · Computer Science 2025-02-05 Boyan Gao , Bo Zhao , Shreyank N Gowda , Xingrun Xing , Yibo Yang , Timothy Hospedales , David A. Clifton

High-resolution seismic reflections are essential for imaging and monitoring applications. In seismic land surveys using sources and receivers at the surface, surface waves often dominate, masking the reflections. In this study, we…

In order to leverage the information embedded in the background state and observations, covariance matrices modelling is a pivotal point in data assimilation algorithms. These matrices are often estimated from an ensemble of observations or…

Methodology · Statistics 2019-10-22 Sibo Cheng , Jean-Philippe Argaud , Bertrand Iooss , Didier Lucor , Angélique Ponçot

Satellite radar altimetry is one of the most powerful techniques for measuring sea surface height variations, with applications ranging from operational oceanography to climate research. Over open oceans, altimeter return waveforms…

Atmospheric and Oceanic Physics · Physics 2017-09-25 Ribana Roscher , Bernd Uebbing , Jürgen Kusche

Time-lapse seismic full-waveform inversion (FWI) provides estimates of dynamic changes in the subsurface by performing multiple seismic surveys at different times. Since FWI problems are highly non-linear and non-unique, it is important to…

Geophysics · Physics 2023-08-21 Xin Zhang , Andrew Curtis

Pre-screening of ship proposals is now employed by top ship detectors to avoid exhaustive search across image. In very high resolution (VHR) optical image, ships appeared as a cluster of abnormal bright pixels in open sea clutter…

Computer Vision and Pattern Recognition · Computer Science 2018-04-26 Viet Hung Luu , Nguyen Hoang Hoa Luong , Quang Hung Bui , Thi Nhat Thanh Nguyen

Four-dimensional variational data assimilation (4D-Var) on a seasonal-to-interdecadal time scale under the existence of unstable modes can be viewed as an optimization problem of synchronized, coupled chaotic systems. The problem is tackled…

Data Analysis, Statistics and Probability · Physics 2015-11-17 Nozomi Sugiura , Shuhei Masuda , Yosuke Fujii , Masafumi Kamachi , Yoichi Ishikawa , Toshiyuki Awaji

Data assimilation is a method that combines observations (that is, real world data) of a state of a system with model output for that system in order to improve the estimate of the state of the system and thereby the model output. The model…

Numerical Analysis · Mathematics 2020-05-18 Melina A. Freitag

Bundle adjustment (BA) is a technique for refining sensor orientations of satellite images, while adjustment accuracy is correlated with feature matching results. Feature match-ing often contains high uncertainties in weak/repeat textures,…

Computer Vision and Pattern Recognition · Computer Science 2021-07-02 Xiao Ling , Xu Huang , Rongjun Qin

A compact and efficient numerical method is described for studying plane flows of an ideal fluid with a smooth free boundary over a curved and nonuniformly moving bottom. Exact equations of motion in terms of the so-called conformal…

Fluid Dynamics · Physics 2020-07-01 Victor P. Ruban

Satellite-based remote sensing missions have revolutionized our understanding of the Ocean state and dynamics. Among them, space-borne altimetry provides valuable Sea Surface Height (SSH) measurements, used to estimate surface geostrophic…

Machine Learning · Computer Science 2024-05-07 Theo Archambault , Arthur Filoche , Anastase Charantonis , Dominique Bereziat , Sylvie Thiria

This paper presents a new variational data assimilation (VDA) approach for the formal treatment of bias in both model outputs and observations. This approach relies on the Wasserstein metric stemming from the theory of optimal mass…

Methodology · Statistics 2020-08-04 Sagar K. Tamang , Ardeshir Ebtehaj , Dongmian Zou , Gilad Lerman

We derive rigorously from the water waves equations new irrotational shallow water models for the propagation of surface waves in the case of uneven topography in horizontal dimensions one and two. The systems are made to capture the…

Analysis of PDEs · Mathematics 2023-11-17 Louis Emerald , Martin Oen Paulsen