Abstract: A new filter structure using the multiple model (MM) algorithm based on the extended Kalman filter (EKF) is proposed to estimate the radome slopes and improve the performance of active radar-guided homing missiles. The filter dynamics are built in the three dimensional engagement scenario and the states are composed of relative position, velocity, missile acceleration and target acceleration. The EKF algorithm is adopted to solve the nonlinear measurement function with radome slope interference. The proposed filter algorithm utilizes pseudo-measurements to update the mode probabilities in the MM algorithm based on a series of possible radome slope models. The estimated results of the slopes are introduced into the EKF to get state estimations without radome interference which generates the guidance law command. Simulation results indicate that the MM-EKF algorithm can estimate the radome slopes effectively and improve the accuracy of the guidance system.

Key words: three dimensional guidance model, radar-guidance, radome slope, extended Kalman filter, multiple model algorithm