“…Multiple targets or components of the target have various micro-movements, such as the precession and nutation of warhead targets [5,6], the swing of sea surface ships [7], the rotation of tank tracks [8], the swing of human arms and legs [9], and the vibration of birds' wings during flight [10,11]. Rotorcraft targets are also an essential type of micro-motion targets [12,13], mainly referring to targets containing rotatable blade components, including helicopters, wind turbines, rotorcraft, multi-rotor drones, and propeller aircraft. Rotor targets can generate micro-Doppler effects and periodic micro-Doppler frequency bands through blade rotation.…”