Estimation Method Based on EKF for Radome Error Slope

Aiming at the problem that radome error of the radar-homing missile produces line-of-sight angle measurement error and affects the stability of the guidance system during flight, this paper establishes seeker servo control system model and analyzes the angle relation under radome error in pitch plane. Then, for the convenience of theoretical analysis, a simplified seeker model is established with the low-order equivalent fitting method, which has the same characteristics as seeker servo control system and reduces the model order significantly. Finally, based on the low-order simplified seeker model, this paper establishes the system equation between line-of-sight angle and angular velocity. Taking radome error slope as the state and line-of-sight angular velocity as measurement, an EKF is established to estimate the radome error slope. The results show that the EKF can accurately estimate radome error slope in many forms, and it can be used in the guidance system for radome error compensation in the future.