Miss Distance Error Analysis of Exoatmospheric Interceptors

A miss distance error analysis of exoatmospheric interceptors with liquid divert thrusters in endgame is presented. The analysis relates miss distance uncertainty to 1) infrared/electrooptic seeker noise, 2) seeker latencies caused by image processing and motion compensation and integration to detect the target on the focal plane, 3) seeker scan angle measurement errors of gyro, 4) range error or time-to-go error, and 5) filtration of all these errors through a Kalman filter for estimating the line-of-sight (LOS) rates. With the relationships developed, the missile designer/analyst can predict a probable miss distance with the hardware parameters of the selected divert thrusters and sensor suite, as well as software parameters of the selected guidance policy. The analyst can also arrive at the LOS rate estimation accuracy requirements about the azimuth and elevation axes, to be achieved by a tracking Kalman filter for specified miss distance statistics. The analysis provides insight and predicts reliably the miss distances expected from Monte Carlo simulations and hardware-in-the-loop laboratory tests. (Author)