Track segments association of ballistic targets based on prediction covariance propagation

During the mid-flight of ballistic target, decoys and debris accompany ballistic missile to fly outside the atmosphere, and these ballistic targets are governed essentially by the Earth’s gravity only. Track breakage is a common issue in a multiple ballistic targets tracking scenario with high speeds, high densities and low relative velocity. How to improve the track continuity by associating the break track segments is a focus of research efforts. Therefore, considering the long flight distance characteristic of ballistic targets, this paper studied the break track segments association problem in the Earth Centered Inertia (ECI) coordinate system (CS), and a new algorithm is proposed. This algorithm first derived the formulas for converting the tracking error covariance matrix from the East-North-Up (ENU) CS to the ECI-CS. Then, in the ECI-CS, the interrupted trajectory is predicted based on the ballistic target dynamics equation, and the covariance prediction is propagated. Finally, based on the extrapolation state, covariance and tracking information after the interruption, a test function is designed to solve the break track segments association problem. Simulation results show that, by using the propagated covariance information, the algorithm proposed in this paper can more effectively solve the break track segments association problem of ballistic targets.