三点法跟踪运载火箭系统跟踪目标弹作匀速直线运动，拦截弹做匀速率运动。里面微分方程是用欧拉法求解的，为了提高精确度，改成四阶龙格库塔法-Tracking system to track the target missile launch vehicle for uniform linear motion, interceptor uniform rate of movement to do. Which is Euler' s method for solving differential equations, in order to improve accuracy and change into a fourth-order Runge-Kutta method