Generic Analysis of Interceptor Design and Tracking System Performance for Boost Phase Intercept

Abstract

This paper describes a series of system design and performance studies for a notional airlaunched interceptor intended for boost phase interception of a ballistic missile target. A candidate launch platform for the interceptor is an unmanned air vehicle loitering in airspace near the target launch site. A notional target from the open literature is used for analysis. The conceptual interceptor is designed from first principles using standard methods. Designs for two target tracking filters based on the Extended Kalman Filter (EKF) and the Unscented Kalman Filter (UKF) are developed. Then tracking accuracy is quantified as a function of measurement noise levels. The effects of tracking errors and prediction interval on errors in the Predicted Intercept Point (PIP) is determined. Then an evaluation of how the PIP errors affect interceptor terminal performance is conducted, using heading errors and line-of-sight pointing errors as metrics. The performance of the candidate system design is then assessed. I. Introduction N the present study, a generic air-launched boost phase intercept system is evaluated. The study considered a notional set of targets obtained from the open literature. A candidate launch platform for the interceptor is an unmanned air vehicle (UAV) loitering in airspace near the target launch site. In the initial work, a generic interceptor missile design is developed from first principles using standard methods from the literature. The interceptor design is based on a set of general guidelines established at the outset of the study. After completion of the interceptor design, a generic tracking system model is developed based on Extended Kalman Filter (EKF) and Unscented Kalman Filter (UKF) estimation techniques. The tracking filter designs are then evaluated against a notional target in a parametric manner for different assumed levels of measurement noise. After quantifying the tracking errors versus measurement accuracy, the study addresses the intercept point prediction problem. Errors in the Predicted Intercept Point (PIP) are determined as a function of tracking system measurement accuracy and the length of the prediction interval. Finally, the effect of PIP errors on interceptor guidance system performance is analyzed. Guidance system errors are evaluated by calculating interceptor heading errors and line-of-sight seeker pointing errors induced by PIP errors. Finally, results of the candidate boost phase intercept system performance analysis are summarized.