Miss distance analysis in a new guidance law

Abstract

This paper presents an analysis of a guidance law that combines pursuit guidance with proportional navigation. The analysis accounts for the presence of measurement noise and autopilot dynamics. Under the assumptions that the measurement noise processes are Gaussian, white, with zero mean, and that the autopilot is ideal, we obtain an analytical expression for the mean square miss (i.e., the expected value of the square of the miss distance), explicitly in terms of the navigation constants. Generally, the mean square miss will then decrease as the navigation constants are increased. We also consider the effect of measurement noise in the presence of a first-order autopilot. Here, numerical simulations suggest that for relatively large values of the autopilot time-constant, increasing the navigation constants will be detrimental to the accuracy of the homing. This result corroborates the findings of previous studies on proportional navigation, where it was shown that increasing the navigation constant shortens the engagement, but degrades accuracy in the presence of autopilot dynamics.