Comparative analysis of the classic ground attack terminal guidance laws

The open loop guidance dynamics and hardware demands in engineering systems of the ground attack terminal guidance laws are analyzed. It shows that the proportional navigation (PN) guidance law has a lower demand of the hardware measuring precision and a faster guidance dynamic than the other 'angle' guidance laws. As the representative of the ground attack terminal guidance laws, a comparative guidance model for the proportional navigation and velocity pursuit (VP) is established. The comparison research work on the guidance precision is implemented employing the non-dimensional technique and method of adjoints when the initial heading error, seeker angle zero position error, seeker noise and target glint noise are introduced into the PN/VP guidance system. The results show that to eliminate the miss distance due to the initial heading error, a long terminal guidance time is necessary for VP and when the terminal guidance time is short, the miss of VP is larger than that of PN. With the increasing of the terminal guidance time, the VP's miss distance due to the seeker angle zero position error approaches to a stable value and cannot be eliminated, while PN can eliminate the miss due to the seeker angle zero position error when the guidance ratio N≥3. In addition, the PN miss distance due to seeker noise and glint noise is larger than VP, implying that when the seeker noise and glint noise is too large, the proportional navigation guidance law is not applicable. Finally, the most appropriate guidance law can be selected according to the relations of the missile system hardware, the guidance signal types, the guidance signal quality and the missile total tactical demands.