基于动态散斑时频特性的合作目标微动参数反演  

Inversion Algorithm for Micro-Motion Parameters of a Cooperative Target Based on Time-Frequency Feature of Dynamic Speckle

作　　者：王利国[1] 李亚清[1] 巩蕾[1] 王谦 Wang Liguo;Li Yaqing;Gong Lei;Wang Qian(School of Photoelectrical Engineering,Xi an Techmological University,Xi'an,Shaanxri 710021,China)

机构地区：[1]西安工业大学光电工程学院,陕西西安710021

出　　处：《光学学报》2021年第2期165-174,共10页Acta Optica Sinica

基　　金：国家自然科学基金(61805190,11504286);陕西省自然科学基础研究计划项目(2019JQ-839,2019JM-238);陕西省教育厅专项科研计划项目(19JK0406);陕西省教育厅重点科研计划项目(20JS059)。

摘　　要：基于激光动态散斑的时频信号,建立了一套适用于角反射器阵列的微动参数反演算法。首先利用物理光学方法推导了角反射器及角反射器阵列激光散斑的实时强度公式,然后基于短时傅里叶变换研究了散斑功率谱形成机制及其数字特征,最后提出了频谱相关法及时频-相幅变换算法,并采用该方法提取了动态散斑时频谱线周期及振幅分布,反演了三种典型运动状态下目标的自旋周期及旋转轴指向。结果表明:基于几个周期的散斑强度序列,所提反演算法可以得到高精度的旋转周期及视线角,但对旋转轴方位角的反演精度相对较差,需要更多的观测数据才能得到满意的结果。In this paper,a set of inversion algorithms for the micro-motion parameters in a retroreflector array was established based on the time-frequency signals of laser dynamic speckles.Firstly,the real-time intensitys formula of laser speckle from a retroreflector and a retroreflector array were derived by a physical optics method.Then,based on the short-time Fourier transform,the formation mechanism and digital characteristics of the speckle power spectrum were studied.Finally,the spectral correlation method and time-frequency to phase-amplitude transform algorithm were proposed,and the algorithm was used to extract the period and amplitude distribution of the time-frequency spectral lines of dynamic speckles.Besides,we made an inversion on the spin period and the direction of the rotation axis of a target in three typical motion states.The results show that the proposed inversion algorithm can obtain the rotation period and line-of-sight angle with high accuracy through speckle intensity signals in a few periods,but the inversion accuracy for the azimuth angle of the rotation axis is relatively poor.It follows that more observation data are required for satisfactory results.

关 键 词：遥感 激光散斑 激光探测 微动参数反演 角反射器阵列 时频分析 

分 类 号：O436.1[机械工程—光学工程]