Line-of-sight interceptor guidance for defending an aircraft

A three-body interception scenario is considered, where an aircraft launches a defending missile as a counterweapon against an incoming, attacking missile. Line-of-sight guidance is investigated as a prospective strategy for the defender missile, with the aircraft being the moving launch platform. Kinematic results on line-ofsight guidance with a moving/maneuvering platform are derived, showing defender-attacker interception for all attack geometries and attacker maneuvers. The speed and maximum terminal acceleration requirements are shown to be considerably lower when compared with a proportional navigation guided defender missile. It is also shown that the attacker pays maximum penalty for an evasive maneuver from the defender if the defender uses line-of-sight guidance. A cooperative guidance law is proposed for the aircraft to maximize the attacker-to-defender lateral acceleration ratio. Simulations are carried out for various attack geometries, with and without the cooperative strategy, showing better relative control effort performance for the former.