Micro-Motion Signature Extraction of Vibrating Targets based on Stepped Frequency Continuous Wave Radar Time-Range Profiles

The echo model of one-point vibrating target for stepped frequency continuous wave (SFCW) radar is established first. Then high resolution range profile of the vibrating target is derived from the model. After the periodic laws of range profile of the target being analyzed, a micro-motion signature extraction method of vibrating targets based on time-range profiles is proposed. To improve the precision of the period estimation of micro-vibrating target extracted by the algorithm amplitude peak search (APS), two improved micro-motion signature extraction algorithms are carried out. One is data preprocessing based amplitude peak search (DPBAPS); the other is amplitude threshold detection (ATD). Simulation experiments indicate that range, vibrating amplitude and vibrating period of the target can be achieved effectively by DPBAPS and ATD under the condition of that signal to noise ratio (SNR) is above -10 dB, and the estimation of the vibrating amplitude is the estimation of the projection of the real vibrating amplitude onto the radar line of sight. The precision of the range and vibrating amplitude estimation of the two improved algorithms is the same as that of APS; however, the precision of the vibrating period estimation of the two improved algorithms is much higher than that of APS and can reach or be superior to the level of the sampling period. More over, the two improved algorithms put forward in this paper could be applied to other periodic moving targets such as rotary targets.