Micro-motion target characteristic extraction method based on micro-Doppler effect

Abstract

The invention discloses a micro-motion target characteristic extraction method based on the micro-Doppler effect. According to the micro-motion target characteristic extraction method based on the micro-Doppler effect, firstly, HHT is introduced into micro-motion target characteristic extraction, an HHT algorithm based on downsampling EMD is put forward for the problem of mode mixing of HHT characteristic extraction, noise-plus EMD is conducted on multi-set data obtained through downsampling of original signals, summation average is calculated, and therefore the problem of the pattern mode mixing in vibration target characteristic extraction of HHT is effectively solved. Noise of the original signals is restrained, signal to noise ratio is improved, the EMD arithmetic complexity of the multi-set data is reduced, arithmetic amount is greatly reduced, arithmetic speed is improved, and the better micro-Doppler characteristic extraction effect is achieved. The advantages of a traditional time-frequency analysis method and an improved HHT algorithm are combined, a micro-Doppler characteristic parameter extraction model based on improved HHT is put forward, and the resolution problem in a traditional time-frequency analysis spectrogram is improved due to the fact that a spectrogram peak value estimation method is added into the model. The micro-motion target characteristic extraction method based on the micro-Doppler effect is used as an auxiliary means for HHT characteristic extraction, and the requirement of improving accuracy and practicability of vibration target characteristic extraction is met.

Description

technical field [0001] The invention relates to a micro-Doppler effect micro-moving target feature extraction method, which is suitable for the field of non-contact target detection and recognition. Background technique [0002] When there is relative motion between the detector and the measured target, a Doppler frequency shift will occur, and this phenomenon is called the Doppler effect. In addition to relative motion, the target itself has other motions such as the rotation of the helicopter propeller, the rotating radar antenna on the ship and other small vibrations or rotations. The phenomenon of broadening the signal frequency caused by its own additional motion, that is, the micro-Doppler effect. It is manifested in the frequency spectrum that there are spectral sidelobes or broadening. This sidelobe or broadening characterizes the unique parameter data of the micro-moving target itself, such as reflecting the electromagnetic characteristics, geometric structure and ...

AI Technical Summary

Problems solved by technology

In the current micro-Doppler feature extraction, most of the traditional time-frequency analysis methods used, such as short-time Fourier transform, WVD, SPWVD, etc., these time-frequency analysis methods have resolution problems in the time domain and frequency domain Or the choice of kernel function, there are great defects in the feature extraction of micro-Doppler, so a better method of micro-Doppler feature extraction is needed, which can extract the micro-Doppler feature parameters well

Images