A parameter design strategy for seeker's field-of-view constraint in impact angle guidance

This note studies the problem of impact angle guidance by considering the seeker's field-of-view angle constraint and proposes a new guidance parameter design strategy based on the classical time-to-go weighted impact angle optimal guidance law. To this end, firstly, the analytic expression of the field-of-view angle throughout the guidance process is presented. It is demonstrated that the max field-of-view angle can be controlled by designing the correct time-to-go weighted parameter and initial guidance conditions. Then, a guidance strategy, which includes the optimal guidance law, guidance condition selection, and guidance parameter design, is given. When using the strategy, the suitable time-to-go weighted parameter is modified to ensure the seeker's field-of-view angle would not exceed the boundary value. Finally, the results of a numerical simulation based on the simple missile-target kinematics are presented; these results validate the proposed strategy.