Iranian Journal of Electrical and Electronic Engineering

In this paper, after defining pure proportional navigation guidance in the 3-

dimensional state from a new point of view, range estimation for passive homing missiles is

explained. Modeling has been performed by using line of sight coordinates with a particular

definition. To obtain convergent estimates of those state variables involved particularly in

range channel and unavailable from IR trackers, nonlinear filters such as sequential U-D

extended Kalman filter and Unscented Kalman filter in modified spherical coordinate

combined with a modified proportional navigation guidance law are proposed. Simulation

results indicate that the proposed tracking filters in conjunction with the dual guidance law

are able to provide the convergence of the range estimate for both maneuvering and nonmaneuvering

targets.