Fourth order predictive, augmented proportional navigation system terminal guidance design with missile/target decoupling

TLDR: In this article, the authors proposed a method for augmenting a noise-adaptive predictive proportional navigation terminal guidance scheme with target and missile information terms and a navigation ratio which is a function of time-to-go.

Abstract: A method for augmenting a noise-adaptive predictive proportional navigation terminal guidance scheme. In a fourth order configuration with noise adaptive varying gain parameters calculated as a function of time-to-go, this system implements an optimal control law to augment proportional navigation with target and missile information terms and a navigation ratio which is a function of time-to-go. By employing a fourth order system, enhanced use may be made of information already available in the guidance computer and missile control system to decouple target motion information from the missile control signals. Decoupled target motion information facilitates blind-mode operation in the end game, the last few seconds before intercept. Decoupled missile control information enables the airframe to be controlled to predefined orientations for aimed warhead applications. This system is particularly useful for high and medium altitude targets and results in significant miss distance improvement for terminal guidance against small maneuvering targets. The system has additional benefits in that it results in nearly optimal miss distance behavior with sensitivity to unmodeled errors being substantially less than that in modern guidance systems.