Optimal guidance with an in route look-angle constraint

A guidance law that enables controlling the look-angle (i.e., the angle between the missile’s velocity vector and the line-of-sight), at some time during the engagement, is proposed. The guidance law can be used to improve the performance of sensors which have look-angle requirements or to maintain the missile’s maneuver advantage over the target perpendicular to the line-of-sight. The problem is posed in the linear optimal control framework and a closed form guidance law is derived for any linear missile dynamics. The performance of the proposed guidance law is evaluated in a nonlinear two dimensional simulations. It is shown that the look-angle can be successfully imposed without forgoing the missile’s intercept capability. It is also demonstrated that against an unpredictable target the proposed guidance law provides an improvement in the miss distance, when compared to the same guidance law without controlling the look-angle.