APPENDIX
We describe the formulas for the Kalman filtering steps here. The notation
we use is the same as that discussed in the section on the Kalman filter.
- Evaluate and using the state equation.
- Find the observation YtandRby observing the system. Note that we
have the matrix Hdefined as follows:
Yt=HXt+vt
- Compute the Kalman gain Kt.
- Evaluate given by.
- Evaluate.
ˆˆ
Ptt||KH Ptt KH KRK
T T
=−() (^11) − 1 ()− +
ˆ
Ptt|
ˆˆ
XKYHXtt||−− 11 +−t( t tt )
ˆ
Xtt|
KPHHPH Rtt=+T()t T
−
ˆˆ
1
ˆˆ
ˆˆ
||
||
XAX
PAPA
tt t t
tt t t
T
−−−
−−−
=
=
111
111
ˆ
Ptt|− 1
ˆ
Xtt|− 1
Kalman Filtering 69