Micro-Doppler Frequency Extraction for Cone-shaped Target with Precession Based on Instantaneous Frequency Estimation

Based on the equivalent scatter point model, the relationship between the micro-Doppler frequencies and the motion parameters of the cone-shaped target with precession is established. Due to the approximately sinusoidal form of the micro-Doppler frequency modulation induced by the precession, an approach to extract the micro-Doppler frequency of the target with precession based on the instantaneous frequency estimation and the RANdom SAmple Consensus (RANSAC) is proposed. In this method, the target echo signal is first divided into several segments. Then each segment of the echo signal approximates to the sum of several components of the Linear Frequency Modulation (LFM) signal, and an algorithm based on the extended Relax method is used to estimate the instantaneous frequency of the each LFM signal. Thus the micro-Doppler curve of each equivalent scatter point is estimated by the RANSAC algorithm. In the simulation experiments, the performance of the proposed method is evaluated via the simulation data and electromagnetic computation simulation data.