Time-varying radome slope estimation for passive homing anti-ship missiles

This paper addresses a time-varying radome slope (RS) estimation problem for passive homing anti-ship missiles. Apart from conventional approaches, the non-linear characteristics of the radome aberration error is taken into account for modeling the RS dynamics. In addition, it is shown that the acceleration dither is necessary for ensuring the observability of the RS estimation with passive seeker measurements. Based on this observation, a linear RS measurement equation is set up by analyzing the seeker response to the high-frequency acceleration dither. Thus, the RS estimation problem can be easily resolved by designing a time-varying Kalman filter. Since the proposed approach adopts a simple linear filter structure, it is suitable for an in-flight real-time RS estimation. Through the computer simulation for a typical ASM-target engagement scenario, the usefulness of the suggested scheme is demonstrated.