DESIGN OF TARGET STATE ESTIMATION ALGORITHM WITH HYBRID MEASUREMENTS

In some missile systems, the information about the target (position/velocity/acceleration) which is measured/calculated by ground radar system is transferred to the missile via an up-link. This information is then utilized in midcourse guidance algorithms until the seeker lock-on is accomplished. If the communication between the ground radar and the missile sustain till terminal phase, this information can be used in advanced terminal guidance algorithms in order to enhance the guidance performance of the missile. In this paper, seeker and radar measurements with different sampling frequencies are integrated by Extended Kalman Filter based estimation algorithm. The system is defined in polar coordinate frame reflecting the 3D missile-target kinematics and the target is assumed to move with constant speed. As a result of this study, the estimation of range to-go and closing velocity is obtained.