Optimal terminal trajectories for clutter crossover avoidance of a variable flow ducted rocket missile

Optimal terminal trajectories have been investigated for the clutter crossover avoidance of a bank-to-turn (BTT) missile equipped with a doppler radar seeker and a variable flow ducted rocket (VFDR). VFDR missiles are thought to be effective against targets such as maneuvering aircraft because the thrust of a VFDR is controllable and the terminal velocity of a VFDR is high. However, when the doppler frequency of the target echo comes into the doppler frequency spectrum of the clutter, especially the doppler frequency spectrum of the seeker's main lobe, the signal-to-noise ratio (SNR) of the receiver signal is heavily degraded. The objective of this research is to derive the optimal terminal trajectories of VFDR missiles to avoid the main lobe clutter. The optimal trajectories are obtained as minimum flight time solutions with a constraint expressing the clutter crossover avoidance, and compared with the optimal trajectories without the constraint. The solutions are obtained numerically using a nonlinear programming method.