Abstract: A PLKF(pseudo-linear Kalman filter) is presented for tracking a moving target using two stations of IRST systems. The initial value of the filer is attained from the pseudo-linear equations, which improves the tracking accuracy and speed of the filter. Results of the simulation of tracking a maneuvering target by PLKF and EKF(extended Kalman filter) illustrate that at the beginning of tracking, the tracking accuracy of PLKF is better than that of EKF; in the near range of the tracking, both the tracking accuracy of PLKF and EKF are better whether the target is maneuvering or not; in the far range of the tracking, the tracking accuracy of PLKF is better than that of EKF when the target maneuvers, but is somewhat worse when the target moves at a constant velocity. From the view of global range, the influence of the moving state of the target is very strong on the tracking accuracy of the EKF and is weak on that of PLKF.

Key words: pseudo-linear Kalman filter, IRSTS, passive tracking