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Main Authors: Kakasenko, Lev, Alexanderian, Alen, Farazmand, Mohammad, Saibaba, Arvind K.
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2505.04004
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author Kakasenko, Lev
Alexanderian, Alen
Farazmand, Mohammad
Saibaba, Arvind K.
author_facet Kakasenko, Lev
Alexanderian, Alen
Farazmand, Mohammad
Saibaba, Arvind K.
contents We consider the problem of state estimation from limited discrete and noisy measurements. In particular, we focus on modal state estimation, which approximates the unknown state of the system within a prescribed basis. We estimate the coefficients of the modal expansion using available observational data. This is usually accomplished through two distinct frameworks. One is deterministic and estimates the expansion coefficients by solving a least-squares (LS) problem. The second is probabilistic and uses a Bayesian approach to derive a distribution for the coefficients, resulting in the maximum-a-posteriori (MAP) estimate. Here, we seek to quantify and compare the accuracy of these two approaches. To this end, we derive a computable expression for the difference in Bayes risk between the deterministic LS and the Bayesian MAP estimates. We prove that this difference is always nonnegative, indicating that the MAP estimate is always more reliable than the LS estimate. We further show that this difference comprises two nonnegative components representing measurement noise and prior uncertainty, and identify regimes where one component dominates the other in magnitude. We also derive a novel prior distribution from the sample covariance matrix of the training data, and examine the greedy Bayesian and column-pivoted QR (CPQR) sensor placement algorithms with this prior as an input. Using numerical examples, we show that the greedy Bayesian algorithm returns nearly optimal sensor locations. We show that, under certain conditions, the greedy Bayesian sensor locations are identical or nearly identical to those of CPQR when applied to a regularized modal basis.
format Preprint
id arxiv_https___arxiv_org_abs_2505_04004
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Bridging the Gap Between Deterministic and Probabilistic Approaches to State Estimation
Kakasenko, Lev
Alexanderian, Alen
Farazmand, Mohammad
Saibaba, Arvind K.
Numerical Analysis
We consider the problem of state estimation from limited discrete and noisy measurements. In particular, we focus on modal state estimation, which approximates the unknown state of the system within a prescribed basis. We estimate the coefficients of the modal expansion using available observational data. This is usually accomplished through two distinct frameworks. One is deterministic and estimates the expansion coefficients by solving a least-squares (LS) problem. The second is probabilistic and uses a Bayesian approach to derive a distribution for the coefficients, resulting in the maximum-a-posteriori (MAP) estimate. Here, we seek to quantify and compare the accuracy of these two approaches. To this end, we derive a computable expression for the difference in Bayes risk between the deterministic LS and the Bayesian MAP estimates. We prove that this difference is always nonnegative, indicating that the MAP estimate is always more reliable than the LS estimate. We further show that this difference comprises two nonnegative components representing measurement noise and prior uncertainty, and identify regimes where one component dominates the other in magnitude. We also derive a novel prior distribution from the sample covariance matrix of the training data, and examine the greedy Bayesian and column-pivoted QR (CPQR) sensor placement algorithms with this prior as an input. Using numerical examples, we show that the greedy Bayesian algorithm returns nearly optimal sensor locations. We show that, under certain conditions, the greedy Bayesian sensor locations are identical or nearly identical to those of CPQR when applied to a regularized modal basis.
title Bridging the Gap Between Deterministic and Probabilistic Approaches to State Estimation
topic Numerical Analysis
url https://arxiv.org/abs/2505.04004