Extraction of Micro-Doppler Frequency From HRRPs of Rotating Targets

Micro-motion dynamics, such as rapid rotation, vibration and spinning motion, impose additional time-varying frequency modulation on the returned radar signals, which is known as the micro-Doppler (m-D) effect. Micro-Doppler frequency is considered as a stable and unique feature, where the uniqueness means that different micro-motions have distinct signatures. Thus, radar m-D feature extraction is of great potential in target classification and identification. This paper presents m-D frequency estimation from the HRRPs of rotating targets in frequency-stepped signal (FSS) based on the circular correlation (CC) coefficients and the circular average magnitude difference (CAMD) coefficients. The m-D frequency of rotating targets can be estimated accurately from the two proposed methods and the corresponding computational cost burden is also investigated. The accuracy and efficiency of the estimations are compared and revealed by the simulated trials and experimental data.