Micro-Doppler extraction of frequency-stepped chirp signal based on the Hough Transform

The micro-Doppler (m-D) effect induced by the rotating parts in a radar target or mechanical vibrations of the target body provides a new approach for auto target recognition. In this paper, the m-D effect in frequency-stepped chirp signal is analyzed. Compared with that in the traditional chirp signal, the m-D effect in frequency-stepped chirp signal appears some new characteristics. To extract these m-D characteristics and so to obtain the micro-motion information of the target for auto recognition, the extended Hough Transform is applied into detecting the parameters of the curves on the range-slow time plane after the analytical expressions of the curves deduced. Computer simulations have proved the validity of the proposed method.