Digital Simulation of Guidance and Control for Exo-Atmospheric Intercept

A mathematical model for various configurations of interceptor missiles operating outside the earth´s atmosphere is described. The associated digital computer simulation program provides means for evaluating the performance of different guidance and control systems and for studying the influence of parameter variations on the overall mission effectiveness. The simulation program also provides a means for establishing dynamic and kinematic criteria for the variable mass interceptor configurations. A complete attack mission, from exo-atmospheric launch to kill, may be carried out in three-dimensional space with all six degrees-of-freedom of the interceptor accounted for in the dynamics. Several models of thrusting and passive tracking may be selected for guidance. The guidance law is based on biased proportional navigation. The program simulates the sensing of the target, control system functions, and interceptor dynamics, all in closed loop form. The control loops contain optional time lags, gains, limits, and shaping neetworks in addition to a White Gaussian noise generator capable of simulating both receiver noise and angular scintillation. The vehicle´s physical characteristics, the control constants, and the intercept mission are entirely arbitrary. The target is a pre-programmed point mass whose trajectory may be described by tabular data, equations for constant acceleration, circular equations, or other options. Output generated consists of time histories of all significant functions and a series of plots generated on a 1403 printer. A simple mission used to demonstrate the capabilities of the program will be discussed.