Mat-1.3656 Seminar on numerical analysis and computational science

Monday, April 7, 2014, room M233 at 14.15, Eirola & Stenberg

Atte Aalto, Aalto?, Department of Mathematics and Systems Analysis
Spatial discretization error in Kalman filtering

It is well known that Kalman filter gives the optimal solution to the state estimation problem for linear discrete time systems with Gaussian initial state and Gaussian input and output noise processes. Kalman filter has also proven to be very robust and so it has been widely adopted in practical applications. When the system is infinite dimensional it has to be discretized in order to be able to numerically compute anything. If the Kalman filter is then applied directly to the discretized system, the result is not optimal.
     In this talk, I will present an optimal one step state estimator for infinite dimensional systems that takes values in a finite dimensional subspace of the system's state space --- consider, for example, a finite element space. In addition, I will derive a bound for the error caused to the state estimate by the state space discretization. The results are demonstrated by a simple numerical example.