Resolution of multiple unresolved targets via dual monopulse with array radar

In the antimissile context, it is important to detect and resolve the unresolved targets in the middle of the ballistic flight. As the targets in group are very close to each other, the traditional techniques are difficult to resolve them. In this paper, we study the problem of grouped target resolution in the angle dimension with array radar. We first establish an echo model of the array radar when there are two unresolved targets in one beam. Then we derive an improved monopulse method based on the maximum likelihood estimation principle, which realizes angle resolution based on a dual monopulse system. Finally, the performance of this method is evaluated by simulations in the cases of varying SNR, inter-target angle separation and intertarget phase/amplitude differences. The simulation results prove that the method performs very well in many aspects, including smaller estimation error and enhanced adaptation to inter-target amplitude difference.