Intercept-Angle Guidance

A new guidance concept is proposed. Implementing it enables intercepting a maneuvering target while also imposing, from early on in the engagement, a predefined angle relative to the target's velocity vector. The scenario of interest is aerial interception between a missile and a maneuvering target. The guidance concept is applicable in all aerial interception geometries: namely, head-on, tail-chase, and the novel head-pursuit. Analytical conditions for existence of these different engagement geometries are derived. The guidance concept is implemented using the sliding-mode approach. The common assumption of flight along an initial collision triangle is not taken, and thus the guidance law is applicable for both midcourse and endgame guidance. The application in the different engagement geometries is studied via simulation. It is shown that the head-on scenario allows the smallest range of intercept angles. It also places the most severe maneuverability requirements on the interceptor. Thus, in some cases, tail-chase or head-pursuit engagements should be considered instead. The choice between the two is dependent on the adversary's speed ratio; for tail-chase, the interceptor must have a speed advantage over its target, while for head-pursuit, it must have a speed disadvantage.