Detection and Imaging of Low-Slow-Small Targets Based on UAV-Mounted Millimeter-wave Radar⋆

• UAV-mounted 78 GHz radar weighs 1.1 km for 0.2 m² RCS. • Distributed imaging resolves 20 cm-spaced reflectors. • Flight endurance >30 min with radar payload. In response to the challenges of limited detection range and insufficient imaging resolution for low-slow-small (LSS) targets in complex clutter environments, this paper proposes a UAV- mounted millimeter-wave radar system integrating lightweight hardware design, multi-chip cascaded power enhancement, and distributed fusion imaging. The developed 78 GHz radar weighs less than 2.5 kg and consumes less than 25 W, enabling UAV deployment with over 30 min endurance. Compared with conventional single-radar configurations, the proposed 8- chip cascaded architecture achieves stable detection beyond 1.1 km for 0.2 m² RCS targets under moderate land clutter. Furthermore, distributed attitude-compensated fusion imaging improves azimuth resolution, enabling discrimination of 20 cm-spaced reflectors and achieving approximately 30% SNR gain over single-radar imaging. The core novelty lies in the integration of lightweight cascaded RF architecture with coherent distributed imaging under UAV motion compensation, providing a practical and scalable solution for long-range high-resolution LSS target detection