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An adaptive Bayesian inference algorithm to estimate the parameters of a hazardous atmospheric release

Author:
Rajaona, Harizo, Septier, François, Armand, Patrick, Delignon, Yves, Olry, Christophe, Albergel, Armand, Moussafir, Jacques
Source:
Atmospheric environment 2015 v.122 pp. 748-762
ISSN:
1352-2310
Subject:
Bayesian theory, Markov chain, Monte Carlo method, algorithms, atmospheric chemistry, field experimentation, teams
Abstract:
In the eventuality of an accidental or intentional atmospheric release, the reconstruction of the source term using measurements from a set of sensors is an important and challenging inverse problem. A rapid and accurate estimation of the source allows faster and more efficient action for first-response teams, in addition to providing better damage assessment.This paper presents a Bayesian probabilistic approach to estimate the location and the temporal emission profile of a pointwise source. The release rate is evaluated analytically by using a Gaussian assumption on its prior distribution, and is enhanced with a positivity constraint to improve the estimation. The source location is obtained by the means of an advanced iterative Monte-Carlo technique called Adaptive Multiple Importance Sampling (AMIS), which uses a recycling process at each iteration to accelerate its convergence.The proposed methodology is tested using synthetic and real concentration data in the framework of the Fusion Field Trials 2007 (FFT-07) experiment. The quality of the obtained results is comparable to those coming from the Markov Chain Monte Carlo (MCMC) algorithm, a popular Bayesian method used for source estimation. Moreover, the adaptive processing of the AMIS provides a better sampling efficiency by reusing all the generated samples.
Agid:
5473942