Estimation of LOS Rates for Target Tracking Problems using EKF and UKFAlgorithms- A Comparative Study

One of the most important problems in target tracking is Line of Sight (LOS) rate estimation for usingfrom PN (proportional navigation) guidance law. This paper deals with estimation of position and LOSrates of target with respect to the pursuer from available noisy RF seeker and tracker measurements.Due to importance of exact estimation on tracking problems most target position and LOS rates havebeen estimated with least error rather than actual values. In this paper, extended Kalman filter (EKF)and unscented Kalman filter (UKF) algorithms are used for estimation of target position in threedimensional(3-D) and LOS rates in elevation and azimuth for seekers and trackers. For comparison ofalgorithms, model of the system was simulated using MATLAB and many tests were carried out.Simulation experiments showed that the efficiency of EKF due to least RMSE had better performance.However, the performance of EKF algorithm dramatically decreased when initializations (initial stateassumption) were not near to real values, which in this condition UKF method provided a moreaccurate approximation. Numerical results from simulations show that the UKF is robust againstuncertainties and has better state estimation accuracy. Therefore, UKF algorithm is appropriate, and itcan run on target tracking systems