Boost-Phase Identification of Theater Ballistic Missiles Using Radar Measurements

Abstract

This paper addresses the problem of identification of theater ballistic missiles during boost phase using radar measurements. Based on the use of the Wald sequential probability ratio test (SPRT), three identification algorithms are presented, corresponding to scenarios of increasing uncertainty. The use of the SPRT allows meeting specified false-alarm and missed-detection probabilities, while minimizing identification time. When the missiles' dynamic models and launch initial conditions (location and time) are completely and accurately known, the SPRT works directly with the raw radar measurements. In other scenarios, including a case where the launch location and launch time are unknown, two extended Kalman filters are used to generate the innovations sequences driving the SPRT. An extensive Monte Carlo simulation study is used to demonstrate the performance of the proposed procedures. Although the identification times and actual error probabilities depend, to some degree, on proper filter tuning, it is shown that reasonable mean identification times can be attained, corresponding to acceptable false-alarm and missed-detection rates, even in the presence of model uncertainties. This performance renders the proposed algorithms viable for the difficult problem considered.