To deal with the uncertainties of the particle filter of the motion model
an improved particle filter EMPF (expectation-maximization particle filter) is proposed. The target states could be estimated more accurately by combining the EM and the PF algorithms
in which the parameters of the motion model are estimated and later confirmed by the EM algorithm. Thus the target states could be estimated more accurately. And the experiment results show that when the target was turning
the algorithm can improve the estimation of the target’s motions dramatically.