Homing guidance is usually referred to as two-point guidance, as there are two reference points dening the engagement geometry: the missile and the target. There has been a lot of interest in the development of homing guidance techniques in the literature over the past 30 years or so. Some of the literature has focused on the development of geometric approaches to guidance algorithm design. The use of differential geometric concepts gives the approach a sound basis for more generalized guidance techniques that allow for curved as well as straight trajectories to be considered for both the target and the missile. Augmented proportional navigation (PN) includes the target acceleration as part of the algorithm but still assumes straight-line interception geometry.