Research On Tracking And Discrimination Methods Based On Mass-to-drag Ratio For Reentry Ballistic Targets

The precision tracking and quick discrimination is the basis of the missile interception, Reentry ballistic target tracking and discrimination is one of the kernel missions for ballistic defense system. Under the related item background of missile attack defend confront, this thesis is the study on the technique of the reentry ballistic target tracking and discrimination.There are four chapters in this thesis. The content of each chapter will be summarized next one by one.The background and significance of this research is briefly specified in chapter 1. Current researches on the technique of reentry ballistic target tracking and discrimination in our country and abroad are analyzed in detail. And the structure of this thesis is given.The technique of ballistic target tracking is analyzed in chapter 2. Firstly the filtering coordinate for tracking is set up, and the model of gravity and atmosphere is studied, and the trajectory generate model and generate simulation trajectory is set up. Secondly, this chapter provides the flow of Extend Kalman Filter (EKF) and the method of filter initialization sets up the dynamics and measurement equation of reentry target; in the last part, an Unscented Kalman Filter (UKF) tracking algorithm based on Runge-Kutta integration is presented, the algorithm can deal with the tracking problems whose dynamic models are denoted by continuous ordinary nonlinear differential equations easily and intuitively, avoid the procedure of discretization and linearization, and the tracking performance of these filters is compared in the simulation.The technique of ballistic target discrimination is analyzed in chapter 3. Firstly, the theory and flow of augment Kalman filter are represented, and the theory and the defeat of the discrimination method based on the estimate of mass-to-drag ratio is analyzed. Secondly, in order to avoid the convergence process of mass-to-drag ratio and ignore the model of atmosphere, the feasibility and applicability of the discrimination method based on differences in relative motion is analyzed through the study on the mass-to-drag ratio, the deceleration characteristics of the target in the atmosphere and the relative velocity and displacement of different targets; in the last part, three discrimination methods are presented by analyzing the motion characteristics of reentry targets: method based on relative velocity, method based on Law of Energy Conservation, method based on difference of Motion state, use the relative velocity, the attenuation of mechanical energy of the unit mass of target, the normalized error of velocity to represent the mass-to-drag ratio to achieve the discrimination of decoys, and their performance is compared in the simulation.In chapter 4, the whole dissertation is summarized, and some suggestions for the future work are brought out.