Research on micro-Doppler feature of spatial target

Zhenyuan Ji,Hongyan Jin,Yun Zhang,Encheng Hu

doi:10.1186/s13638-017-0963-7

Zhenyuan Ji, Hongyan Jin + Show 2 more

Open Access

https://doi.org/10.1186/s13638-017-0963-7

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Abstract

The micro-Doppler (m-D) effect which is also called micro-motion effect is a kind of physical phenomenon, which is often produced in ISAR imaging of space targets. When the space target has a micro-Doppler effect, it will produce frequency modulation for the radar echo and cause serious interference to ISAR imaging of the target. In this paper, the micro-spin model is modeled, and the echo of micro-spin model scattering point is processed respectively by short-time Fourier transform (STFT), Wigner-Vile Distribution (WVD), and pseudo-Wigner-Vile Distribution (PWV), and the micro-Doppler curve is derived. On this basis, for the space target with spin components, this paper introduces an ISAR imaging algorithm using the micro-Doppler removal based on STFT and proposes an improved algorithm based on rigid body parameter estimation, which can obtain better imaging results.

Highlights

The concept of micro-Doppler (m-D) is firstly proposed by V.C
We introduce an ISAR imaging algorithm which can effectively remove the micro-Doppler effect
4.2 An improved algorithm based on rigid body parameter estimation From the signal model simulation results shown in Fig. 3, we can see that the main lobe of the recovered singlefrequency signal is widened and has obvious side lobes, this is because the most important step of the method described in Section 4.1 is to remove the larger amplitude elements in the time-frequency plane

Summary

Introduction

The concept of micro-Doppler (m-D) is firstly proposed by V.C. Chen of the US Naval Research Laboratory [1], which collectively refers to tiny movements such as vibration, rotation, and accelerated movement other than some parts of the target or target. The modulation of these tiny movements on the radar echo spectrum is called the micro-Doppler effect. The physical essence of micro-Doppler is the Doppler effect of the relative distance between the equivalent scattering center of the target and the phase center of the radar antenna as the micro-motion changes. The scattering center has a constant position and phase, and the scattering intensity varies little with frequency. This approximation is the basis of the current micro-Doppler mechanism research on target characteristics and the basis of the establishment of micro-Doppler mathematical model [1]. From the literature point of view, the research contents of radar micro-moving target characteristics can be summarized as micro-target radar echo modeling, microDoppler signal separation, micro-Doppler feature extraction, micro-motion target imaging, and micro-Doppler characteristics of the target classification and identification [2]

Construction of point scattering model for micro-spin target

Findings

Conclusions