Micro-Doppler characteristics of sliding-type scattering center on rotationally symmetric target

The feature of micro-motion is one of the most effective features used for radar recognition in midcourse phase. At present, the study of feature extraction and recognition is usually based on the assumption that the micro-motion of the scattering center and warhead itself is the same, and the radar echo is sinusoid-FM signal. However, this assumption ignores the fact that the scattering center would slide on the warhead with the change of the aspect angle. In this paper, a complete micro-motion model is set for the scattering centers of different positions on the warhead, and the mathematical expression of the micro-Doppler of the sliding-type scattering center is obtained for the first time. The approximation of Taylor expansion under the background of missile confrontation is studied subsequently. The curve of this micro-Doppler is not the generally assumed sinusoid. Dynamic measurement of a precessional target in microwave anechoic chamber is done to vividly observe the sliding feature of the scattering center. The measurement results agree with the theoretic analysis in this paper. This research on micro-Doppler characteristics of sliding-type scattering center provides a more accurate model for the micro-motion simulation and feature extraction of precessional warheads.