湍流大气中微运动粗糙目标散斑场高阶矩和动态特性研究

项目名称： 湍流大气中微运动粗糙目标散斑场高阶矩和动态特性研究

项目编号： No.11504286

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 王利国

作者单位： 西安工业大学

项目金额： 20万元

中文摘要： 空间目标微运动测量是激光散斑测量技术的一项重要应用，广泛用于遥感、空间探测、弹道导弹防御、防空作战和监视等领域。但是由于湍流大气的干扰，激光散斑的时间-空间分布特性都会发生明显的变化，从而给测量结果造成较大误差。为了对测量结果进行修正，有必要对湍流大气影响下的微运动粗糙目标散斑时-空特性进行研究。本项目在粗糙目标散射场基尔霍夫理论的基础上进行合理近似，建立粗糙目标散斑场的惠更斯－菲涅耳积分表达式。结合Rytov理论和广义惠更斯-菲涅耳原理，建立湍流大气中微运动粗糙目标回波强度起伏时间-空间相关函数表达式，数值分析湍流大气对微运动粗糙目标散斑场相干长度、相关时间和归一化强度方差的影响。最后把分步傅立叶算法推广到微运动粗糙目标和动态湍流条件下，数值仿真湍流大气中的动态散斑场，统计分析散斑相干长度和相关时间，对理论结果进行了对比验证。本项目的研究可为湍流大气中散斑测量技术提供理论依据和技术支撑。

中文关键词： 大气湍流；动态散斑；强度起伏时间-空间相关函数；分步傅立叶算法

英文摘要： The micro-motion detection of a spatial object is an important application of laser speckle measurement technolog, which is widely used in many areas, such as, remote sensing, space detection, ballistic missile defense, air defense operation and monitoring. However, because of the existance of the atmoshperic turbulence, the temporal and spatial characteristics of the speckle field may be greatly disturbed, which will introduce a large error to the measurement. Therefore, it is necessary to research the characteristics of the speckle field from a rough object in micro-motion in turbulence. The Huygens-Fresnel integral expression of the speckle field are established by introducing reasonable approximations on the base of the Kirchhoff theory about electromagnetic scattering from a rough target. The temporal-spatial correlation function of the intensity of the speckle field in turbulence are derived by combining the Rytov theory and the Extended Huygens-Fresnel principle. The effect of atmospheric turbulence on the correlation length, the correlation time and the normalized variance of the intensity of the speckle field are numerically analyzed. Finally the Slip-Step Method is extented to the simulation of the speckle field from a rough object in mico-motion in turbulence, the correlation length and correlation time are statistically calculated and compared with the theoretical results. The results of the research will provide a theoretical basis and technical supporta for the application of laser speckle measurement technolog in atmospheric turbulence.

英文关键词： atmospheric turbulence;dynamic speckle; temporal-spatial corraletion function of the inte;Slip-Step Method