This paper deals with the robust minimum variance filtering problem for Lin
ear time-varying systems subject to a measurable input and to norm-bounded
parameter uncertainty in the state and/or the output matrices of the state-
space model, The problem addressed is the design of linear filters having a
n error variance with a guaranteed upper bound for any allowed uncertainty
and any input of bounded energy. Three types of input signals are considere
d: a signal that is a priori known for the whole time interval, an unknown
signal of very large bandwidth that is perfectly measured on-line, and a la
rge bandwidth signal that is measured ahead of time in a fixed preview time
interval, Both the time-varying finite-horizon and stationary infinite-hor
izon cases are treated.