A hardware-in-the-loop simulation for LOS rate estimation of strapdown seeker based on EKF

In order to capture the target more quickly, some seekers of air-to-ground missile were intentionally installed with an angle between the optical axis and the body axis in vertical plane, which is defined as the pitching angle of optical axis. Aiming at solving the problem that the strapdown seeker cannot measure the line-of-sight (LOS) rate directly, a LOS rate estimate method based on Extended Kalman Filter (EKF) has been presented and a hardware-in-the-loop simulation experiment using a real strapdown laser seeker with a pitching angle of optical axis was made to evaluate the scheme in this paper. It shows that the LOS angle and rate obtained from a real strapdown laser seeker can basically match with that derived from a mathematical model of a gimbaled laser seeker. With an accurate Circular Error Probable (CEP), it provides feasibility and effectiveness for engineering applications of a real strapdown laser seeker with a pitching angle of optical axis utilizing the EKF algorithm to estimate the LOS rate.