Analysis of radar micro-Doppler signatures from rigid targets in space based on inertial parameters

Micro-Doppler features have intrinsic relations with the physical properties of objects, which provide great potential for use in the target discrimination. A model and theoretical analysis of micro-Doppler based on inertial parameters for aerospace rigid targets are presented. According to the attitude kinematics in space, mathematical formulas of the micro-Doppler model based on inertial parameters are derived without the limitation of micro-motion types. Moments of inertia and initial rotational angular velocities are used to analyse their impact on micro-motions and micro-Doppler of free rigid targets. After the simulation of radar echoes from objects with various micro-motions, the joint time-frequency analysis is then utilised to demonstrate the time-varying micro-Doppler features and confirm the effectiveness of the model and theoretical analysis. The proposed method highlights the relationship between the model and the attributes of objects and gets rid of the restriction on the specified target shapes, which illustrates more explicit physical meaning and flexibility in the application.