Trajectory optimization for air-to-surface missiles with imaging radars

The use of trajectory optimization techniques is presented for the terminal guidance of an air-to-surface missile using a Doppler beam sharpening (DBS) radar seeker. The terminal guidance problem is characterized by a stealthy terrain-following phase that is followed by a climb and dive onto the target (a "bunt" trajectory). The imaging properties of DBS radars impose additional azimuth plane constraints on the trajectory that have to be incorporated into the optimization process. The various mission phases are interrelated, and the performance objectives come into conflict with the hardware constraints. The trajectory optimizer is used to generate offline open-loop controls that satisfy the various mission requirements. Numerical examples are used to illustrate the method and its efficacy.