Radome aberration estimation and target tracking with line-of-sight angle measurement

Abstract

This thesis covers radome aberration estimation and target tracking with line-of-sight angle-only measurement. When the microwave seeker on anti-ship missile is jammed by the anti-Electronic Counter Measures (anti-ECM) equipped on target fleet or battleship, line-of-sight angle is the only available measure-ment. In this case, since the information on target state variables is essential for terminal homing guidance, the target state variables are needed to be estimated accurately from line-of-sight angle-only measurement. However, because the signal from target is refracted by radome, structure attached at missile nose to protect seeker, line-of-sight angle measurement contains erroneous component, called radome aberration. Thus, it is required to estimate and compensate the effects of radome on line-of-sight angle measurement for precise target state estimation. In this thesis, radome aberration and target state estimation system is modeled and its local observability conditions are obtained. Revised Adaptive Intermittent Maneuver (RAIM) is proposed to enhance the observability of this estimation system. Radome aberration and target state estimator is designed by applying Extended Kalman Filter (EKF) algorithm. Numerical simulations are conducted to analyze the characteristics and performance of the observability enhancement methods and the state estimation algorithm introduced in this thesis.