Title
Efficient spatio-temporal Gaussian regression via Kalman filtering
Abstract
We study the non-parametric reconstruction of spatio-temporal dynamical processes via Gaussian Processes (GPs) regression from sparse and noisy data. GPs have been mainly applied to spatial regression where they represent one of the most powerful estimation approaches also thanks to their universal representing properties. Their extension to dynamical processes has been instead elusive so far since classical implementations lead to unscalable algorithms or require some sort of approximation. We propose a novel procedure to address this problem by coupling GPs regression and Kalman filtering. In particular, assuming space/time separability of the covariance (kernel) of the process and rational time spectrum, we build a finite-dimensional discrete-time state-space process representation amenable to Kalman filtering. With sampling over a finite set of fixed spatial locations, our major finding is that the current Kalman filter state represents a sufficient statistic to compute the minimum variance estimate of the process at any future time over the entire spatial domain. In machine learning, a representer theorem states that an important class of infinite-dimensional variational problems admits a computable and finite-dimensional exact solution. In view of this, our result can be interpreted as a novel Dynamic Representer Theorem for GPs. We then extend the study to situations where the spatial input locations set varies over time. The proposed algorithms are tested on both synthetic and real field data, providing comparisons with standard GP and truncated GP regression techniques.
Year
DOI
Venue
2017
10.1016/j.automatica.2020.109032
Automatica
Keywords
Field
DocType
Spatio-temporal Gaussian processes,Kalman filter,Machine learning,Representer theorem,Separable kernel functions
Kernel (linear algebra),Extended Kalman filter,Mathematical optimization,Fast Kalman filter,Kalman filter,Gaussian,Artificial intelligence,Gaussian process,Representer theorem,Mathematics,Machine learning,Covariance
Journal
Volume
Issue
ISSN
118
1
0005-1098
Citations 
PageRank 
References 
0
0.34
0
Authors
5
Name
Order
Citations
PageRank
Marco Todescato1276.63
Carron, A.2284.97
Ruggero Carli389469.17
Pillonetto Gianluigi487780.84
L. Schenato583972.18