Bistatic Micro-Doppler Feature of the Precessing Cone-shaped Warhead

Micro-motion feature is one of the effective features used for radar target recognition in the middle section of the ballistic curve. Using the scattering centers of the cone-shaped warhead analyzed by the Geometrical Theory of Diffraction (GTD), it is concluded that the cone-shaped warhead has three scattering centers, one is at the conical point, and the other two are the points where the projection of the bistatic bisector on the conical bottom intersects the edge of the conical bottom, firstly. Then the micro-Doppler (m-D) models of the scattering center at the conical point and two slip-type scattering centers on the edge are derived. They are similar with the monostatic m-D models of the scattering centers when the radar locates on the bistatic bisector, and the amplitude ratio of the m-D in the bistatic radar and monostatic radar is the cosine of the half of the bistatic angle. It coincides with the monostatic-bistatic equivalence theorem. Three correlations of the m-D of the three scattering centers are founded by analyzing their m-D expressions. Finally, the bistatic Radar Cross Section(RCS) of the cone-shaped warhead model are calculated by using FEKO. The theoretic analysis of the m-D expressions is verified from the time-frequency analysis on the bistatic scattering coefficients.