Experimental analysis on micro-Doppler characteristics of rotors

In order to analyze the micro-Doppler effect of rotor and its main parts, a measurement method using microwave anechoic chamber was suggested, and its reliability was verified by some examples. A series of experiments on some rotors with two kinds of blades and with different numbers of blades indicate that echoes of various scattering components can be separated by frequency in the micro-Doppler effect. The number of blades and the rotation speed of rotor do not affect the analysis and estimate of the micro-Doppler effect. It can also be concluded that the micro-Doppler effect only depends on the motion characteristic of the rotor. Combined with target characteristics of helicopter, micro-Doppler effect of rotor was extracted from experimental data using short fast Fourier transform, and the frequency characteristic, wide frequency band and polarization characteristic were obtained by analyzing the influences of incident wave and geometry characteristics of rotor on micro-Doppler effect.