Biased PNG for target observability enhancement against nonmaneuvering targets

This paper proposes a biased proportional navigation guidance (BPNG) law providing enhanced target observability for passive homing missile systems against a nonmaneuvering target. After examining the line-of-sight (LOS) rate equation, which is an important parameter of target observability and which reveals that the LOS rate is proportional to the rate of cross-range deviation, a bias term of BPNG is formulated using the rate of cross-range deviation to generate an additional LOS rate. The closed-form trajectory solution of the proposed guidance law is derived, and its capturability and characteristics are then investigated. Using numerical simulations, the performance of the proposed guidance law is determined in conjunction with a target state estimator.