Chattering Mitigation in Monopulse Radar Using HOSM

Abstract

Tracking radar uses pencil beam to track the true range and bearing of target. They are used in several applications like to supervise the specific air routes, military applications, radio astronomy etc. Monopulse tracking radars are under study since many past years. Monopulse tracking radars have the benefit over other radar systems using conical scanning method because they are not affected by the fluctuations in the strength of target echo. Monopulse radar detects the range and bearing of target by comparing the amplitudes of received beams. Monopulse tracking using IMM, Kalman and particle filter are some of the algorithms that have been proposed in the literature. Monopulse tracking in the robust framework has not been observed in the literature yet. In monopulse radar the error cannot be minimized past a certain value, instead it fluctuates within a certain limit. Thus beam of monopulse radar always has an oscillatory motion during target tracking. This oscillatory motion can be described by chattering phenomena. The ability of a monopulse radar to efficiently measure the target angle is greatly reduced by the chattering phenomena. This work focuses on removing the chattering phenomena using a model free Smooth Super Twisting Controller while estimating the true target trajectory. Smooth Super Twisting Algorithm is used for this purpose as it is independent of model parameters. Undesirable chattering in tracking target trajectory is shown to be suppressed up to a great extent.