“…This class of system is known as Markovian jump linear systems (MJLS). When only an output of the system is available, and therefore the values of the jump parameter are not known, the problem of optimal and sub-optimal ®ltering has been addressed in Ackerson and Fu (1970), Chang and Athans (1978), Tugnait (1982 a, b), Blom and BarShalom (1988), Bar-Shalom and Li (1993) and Dufour and Elliott (1997) among other authors, under the hypothesis of Gaussian distribution for the disturbances, and by Zhang (1999Zhang ( , 2000 for the nonGaussian case. Since the optimal estimator requires exponentially increasing memory and computation with time, sub-optimal algorithms are required.…”