Jalili-Naini - Research Assistant, Department of Aerospace Engineering, Shiraz University of Technology, Tehran, Iran
Pourtakdoust - Associate Professor, Department of Aerospace Engineering, Shiraz University of Technology, Tehran, Iran

An erplici nidcourse / terminal guidance strategy is derived by considering the approximate models for drag and thrust in the presence of gravity and autopilot dynamics. The guidance/ control system is assumed as a linear time- variant arbitrary – order, the zero- effort miss differential equalion is oblained in a way that three class of guidance laws namely, optimal fuel , optimal energy, and closed – loop explicit strategy, can be obtained by available methods for minimum and nonminimum phase autopilots. The resulting guidance lows have the structure of a guidance gain multiplied by the zero-effort miss. Several thrust/drag models are also considered and discussed to obtain the zero – effort miss equation.

Optimal , explicit , midcourse guidance