Misguided resistance using extended Kalman filter for imaging seeker

Abstract

Fake targets had essential effect on target trace and guidance information extraction. Measures based on extended Kalman filter were recommended in this paper. The model of an imaging seeker was established firstly. Then the interfered model that the imaging seeker was misguided by the fake targets was introduced. The process how the fake targets misguided the imaging seeker was analyzed. An extended Kalman filter was established in the sphere coordinates, which could help to enhance the estimate level. The measurement of the seeker was transformed to the suitable information to spur the extended Kalman filter. The strategies were composed of four stages. Before the fake targets appeared, the extended Kalman filter estimated the motion information and the trend of the target quickly. When the fake targets appeared, the motion of the seeker will be controlled with the information predicted by the extended Kalman filter. The measured information of the seeker will not be used as stimulus to the extended Kalman filter until the true target was identified. After the true target was chosen, the seeker averted to the real target, and the angular information of line of sight measured by the seeker would be used to ensure the stability of the extended Kalman filter. When the transit time of the seeker from the previous direction to the target was finished, the rate of line of sight will be used to make the extended Kalman filter converged quickly. Theoretical analysis and simulation results show that the method is reasonable and efficient.