Front shape similarity measure for shape-oriented sensitivity analysis and data assimilation for Eikonal equation
ROCHOUX, Mélanie
Centre Européen de Recherche et de Formation Avancée en Calcul Scientifique [CERFACS]
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Centre Européen de Recherche et de Formation Avancée en Calcul Scientifique [CERFACS]
ROCHOUX, Mélanie
Centre Européen de Recherche et de Formation Avancée en Calcul Scientifique [CERFACS]
Centre Européen de Recherche et de Formation Avancée en Calcul Scientifique [CERFACS]
MOIREAU, Philippe
Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine [M3DISIM]
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Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine [M3DISIM]
Langue
en
Article de revue
Ce document a été publié dans
ESAIM: Proceedings and Surveys. 2018p. 258 - 279
EDP Sciences
Résumé en anglais
We present a shape-oriented data assimilation strategy suitable for front-tracking problems through the example of wildfire. The concept of " front " is used to model, at regional scales, the burning area delimitation that ...Lire la suite >
We present a shape-oriented data assimilation strategy suitable for front-tracking problems through the example of wildfire. The concept of " front " is used to model, at regional scales, the burning area delimitation that moves, undergoes shape and topological changes under heterogeneous orography, biomass fuel and micrometeorology. The simulation-observation discrepancies are represented using a front shape similarity measure deriving from image processing and based on the Chan-Vese contour fitting functional. We show that consistent corrections of the front location and uncertain physical parameters can be obtained using this measure applied on a level-set fire growth model solving for an eikonal equation. This study involves a Luenberger observer for state estimation, including a topological gradient term to track multiple fronts, and of a reduced-order Kalman filter for joint parameter estimation. We also highlight the need – prior to parameter estimation – for sensitivity analysis based on the same discrepancy measure, and for instance using polynomial chaos metamodels, to ensure a meaningful inverse solution is achieved. The performance of the shape-oriented data assimilation strategy is assessed on a synthetic configuration subject to uncertainties in front initial position, near-surface wind magnitude and direction. The use of a robust front shape similarity measure paves the way toward the direct assimilation of infrared images and is a valuable asset in the perspective of data-driven wildfire modeling.< Réduire
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