Aim point guidance: an extension of proportional navigation to the control of terminal guidance

This paper develops a two loop guidance algorithm that extends proportional navigation (PN) algorithm to control the terminal angle between target and missile velocity vectors, hence controlling the terminal geometry. The inner loop is standard proportional navigation. This is used as it has been shown to be robust and is well established. It is also easy to implement. An outer loop is placed around the PN algorithm that controls the demanded sightline rate. This allows the engagement geometry to be controlled. The theory showing the local stability properties is developed and simulation demonstrates the effectiveness of the algorithm.