A Modified Midcourse Guidance Law Based on Generalized Collision Course

In this paper, analytical solution of the generalized collision coutse (gee) ispresented considerino apptoximate models fot draq and thrust in the presence ofgmvity. the geeis near optimal fot a considerable flight time toward the end.therejore, guidance laws based on gee only need modification for the first stageof flight. the proposed guidance law is a modification of midcourse siratcqiesbased on the gge and its implementation issues. a tecursive relation [orestimation of time-to-go for the geeis presented in order to reduce the onboardcomputational burden. two other recursive relations for time-to-go are obtainedfot optimal guidance laws. the relations can be used for both mulcourseand terminal applications. for an aetodynamically controlled interceptor, theguidance law produces the commanded acceleration in the direction normal toits velocity vector or' apptoximately normal to its body axis. simulation resultsshow that the presented stmtegy is superior to the midcourse guidance lawsbased on geefor a qreater final velocity.