Abstract

A nonlinear differential equation of the Riccati type is derived for the covariance matrix of the optimal filtering error. The solution of this “variance equation” completely specifies the optimal filter for either finite or infinite smoothing intervals and stationary or nonstationary statistics. The variance equation is closely related to the Hamiltonian (canonical) differential equations of the calculus of variations. Analytic solutions are available in some cases. The significance of the variance equation is illustrated by examples which duplicate, simplify, or extend earlier results in this field. The Duality Principle relating stochastic estimation and deterministic control problems plays an important role in the proof of theoretical results. In several examples, the estimation problem and its dual are discussed side-by-side. Properties of the variance equation are of great interest in the theory of adaptive systems. Some aspects of this are considered briefly.

Keywords

MathematicsRiccati equationApplied mathematicsCovarianceCovariance matrixStochastic differential equationDifferential equationAlgebraic Riccati equationPartial differential equationSmoothingDuality (order theory)First-order partial differential equationNonlinear systemMathematical analysisAlgorithmStatistics

Affiliated Institutions

Related Publications

Approximations to optimal nonlinear filters

Let the signal and noise processes be given as solutions to nonlinear stochastic differential equations. The optimal filter for the problem, derived elsewhere, is usually infini...

1967 IEEE Transactions on Automatic Control 310 citations

Applied Optimal Estimation

This is the first book on the optimal estimation that places its major emphasis on practical applications, treating the subject more from an engineering than a mathematical orie...

1974 CERN Document Server (European Organi... 6388 citations

Publication Info

Year
1961
Type
article
Volume
83
Issue
1
Pages
95-108
Citations
6246
Access
Closed

External Links

Social Impact

Social media, news, blog, policy document mentions

Citation Metrics

6246
OpenAlex

Cite This

R. E. Kalman, R. S. Bucy (1961). New Results in Linear Filtering and Prediction Theory. Journal of Basic Engineering , 83 (1) , 95-108. https://doi.org/10.1115/1.3658902

Identifiers

DOI
10.1115/1.3658902