An Airborne Passive/Active Electro‐Optic Sensor System for Theater Ballistic Missile Defense

An airborne passive/active surveillance aircraft-based, electro-optic sensor system, named Gatekeeper, is being developed for the US Navy Theater Ballistic Missile Defense Program. The sensor is designed to detect theater ballistic missiles (TBMs), either in boost or post-boost phase, and make precision three-dimensional measurements of the TBM's post-boost, ballistic trajectory with sufficient state-vector accuracy for handover to naval, air and land based missile defense systems. The sensor includes a dual-band IRST for acquisition, a precision angle tracker (MWIR focal-plane array and high-bandwidth mirror), and a short-pulse, direct detection laser radar. The sensor subsystems are coupled and controlled by a sophisticated multiprocessor computer control system. The system has a highly compressed engagement timeline resulting in a substantial target handling capacity. This paper describes the sensor, its specifications, and performance in terms of the accuracy of the state-vector, and its target handling capability in a realistic engagement scenario.