Noise distribution arising in certain applications frequently deviates
from the assumed gaussian model, often being characterized by heavier
tails generating the outliers. Since, in the presence of outliers, th
e performance of a Kalman filter can be very poor, a statistical appro
ach-named QQ-plot-is suggested to make the Kalman filter more robust.
In addition, the first and the second-order moments of noise processes
are estimated simultaneously with the system states, using the QQ-plo
t of the noise samples generated in the 'robustified' Kalman filter al
gorithm. Results of simulation demonstrating the robustness of the pro
posed state estimators are also included.