Analysis of rotating structures for stepped frequency radar

Micro-Doppler caused by micro-motion structures contains movement and structure information which is useful for radar target recognition. The micro-motion modulation in high range resolution profile (HRRP) for stepped-frequency radar (SFR) is quite different forms that in spectrum for Doppler radar. Taking the basic micro-motion, rotation, as an example, this paper deduces its signal model for stepped frequency radar. Result shows that there exhibits a sinusoid shift of scattering centre’s position in HRRP sequence. A fast approach based on Hough transform is proposed to extract rotation parameters from HRRP sequence. Simulated and experimental results verify the correctness of the signal model and the extraction method.