The DD-R27 medium-range X-band four-element array radar 1, Product Overview The DD-R27 medium-range X-band four-element array radar is outfitted with a fully solid-state, fully coherent, and pulse Doppler system. This setup enables it to conduct all-weather detection and early warning of "low, small, slow" targets. Through the utilization of machine learning and AI recognition technologies based on "micro-Doppler signatures" and "flight path features," the system at