On the feasibility of "hit-to-kill" in the interception of maneuvering targets

Earlier generations of interceptor missiles were not designed for a direct hit. Due to the vulnerability of aircraft structures miss distances of a few meters, compatible with the lethal radius of the missile warhead, were considered admissible. The need for a "hit-to-kill" accuracy came with the requirement of intercepting tactical ballistic missiles (possibly carrying nonconventional warheads) and was recently demonstrated against such nonmaneuvering targets. However, by using classical guidance and estimation methods against highly maneuvering targets a similar accuracy is not feasible. In order to achieve improved performance a nonorthodox mindset, leading to a new approach of guidance law design, is necessary. This approach is based on formulating the problem as a pursuit-evasion game and on explicit consideration of the estimator performance in the guidance law synthesis. Moreover, the mathematical model of the interception should allow time varying velocities and maneuverabilities, which are inherent features of ballistic missile defense scenarios. In this paper a new guidance law, integrating all three elements, is presented. Testing this guidance law in a generic, but realistic, ballistic missile defense scenario by Monte Carlo simulations demonstrates very encouraging improvements in homing accuracy, but also indicates that for a "hit-to-kill" further improvements are needed