Research On The Amplitude Estimation Method Of Vibration Target Echo Signal

Radar target recognition technology has become a hot research area nowadays.Besides target features of shape and material etc., micro-motion characteristics, such as rotation or vibration, which are hardly changed, have also attracted widespread attention.One of the key of target recognition is to estimate characteristic parameter of micro-motion effectively, such as amplitude,frequency etc. This paper considers vibration target as the research object, and makes a series of research on its parameter estimation method of echo signal, including basic principle, amplitude estimation, clutter suppression and system design, etc.First of all, this paper describes and analyzes the basic principle of vibration target detection, including theoretical formula of echo signal, micro-Doppler shift and signal processing method etc., and mainly analyzes spectrum analysis and time-frequency analysis method.Then the amplitude estimation method of vibration target is studied. By analysis and comparison of the existing amplitude estimation method, the results show that: the harmonic peak ratio method is mainly used for target with small amplitude, and the estimation error is large because the peak is not accurate; Peak estimation method based on time-frequency analysis is generally used for target with large amplitude, and the estimation error is limited by time-frequency resolution. A new method of target amplitude estimated by the number of spectral lines is proposed. This method can be used whatever large amplitude target or small amplitude target, and has good performance.And then clutter suppression under non-ideal conditions is analyzed. Due to target amplitude estimation affected seriously by the clutter, it is necessary to suppress clutter.MTD is commonly used for moving clutter suppression. However, at present, it is mainly aimed at target with uniform or approximate uniform motion. This paper studies the MTD inhibition effect of vibration target, and the results show that MTD is effective for clutter suppression when clutter is outside the target spectral lines, but not when clutter is between the spectral lines.At last, a target detection system based on FPGA is designed, including the overall design, hardware design and software design, etc. Test results show that this system can real-time display vibration target spectrum.