A guidance method on seeker's field of view and impact angle constraint

A guidance method was proposed, considering seeker field of view constraints and impact angle constraint, for the reason that the seeker look angle of air to ground weapon may overstep the field of view and lose the target when it follows the optimal trajectory shaping guidance law to achieve large impact angle. An analytic expression of seeker look angle was deduced based on the assumption of linearization model and small angle. The factors that influence seeker look angle and the range of maximum seeker look angle were analyzed. On this basis, the guidance method satisfied the seeker field of view constraints through changing the initial line of sight angle or relaxed impact angle constraints was put forward for different air to ground weapons. The select principle of initial line of sight value and the maximum impact angle calculation method were also presented. Numerical simulations verified the effectiveness of the seeker look angle theoretical expressions and the proposed guidance method.