基于双偏光数字全息的混合相云三维分布表征及探测机理研究

云中冰晶及过冷水滴的识别探测是飞机结冰环境预警及大气探测的主要研究任务之一。数字全息技术在大气粒子的三维测量上具有巨大应用潜力，但采用数字全息技术针对结冰云或混合相云中的局部冰粒和过冷液滴的区分识别，以及确定云层中液滴和冰晶的三维空间粒子浓度分布等问题还需要进一步探索研究。本课题拟采用双偏振态数字全息技术对云层液滴及冰晶粒子进行识别及三维测量，通过数字全息重建的偏振信息特征来表征云相位信息，根据数字全息图构建云粒子三维空间分布，实现对云层过冷水滴和冰晶粒子的区分识别及浓度分布的探测。研究内容主要包括：过冷水滴及冰晶粒子的光散射全息模型、基于数字全息三维重建的偏振特征提取、数字全息与偏振成像相结合的三维粒子空间分布模拟仿真和实验测量研究等。本项目探测方法可为飞机结冰环境预警和大气探测提供理论依据和实验测试手段。

The identification and detection of ice crystals and supercooled water droplets in clouds is one of the main research tasks of aircraft ice environment warning and atmospheric detection. Digital holography has great potential in the three-dimensional measurement of atmospheric particles. However, using digital holography to distinguish and identify local ice particles and supercooled droplets in iceing clouds or mixed phase clouds and to determine the three-dimensional spatial particle concentration distribution of droplets and ice crystals in clouds needs further exploration. In this project, double polarized digital holography is used to identify and measure cloud droplets and ice crystal particles, and to characterize cloud phase information by polarization information features of digital holographic reconstruction. According to the digital hologram, the three-dimensional spatial distribution of cloud particles is constructed to distinguish and identify cloud supercooled water droplets and ice crystal particles and detect concentration distribution. The research contents mainly include that the optical scattering holographic model of supercooled water droplets and ice crystal particles, polarization feature extraction based on digital holographic 3D reconstruction, simulation and experimental measurement of 3D particle spatial distribution combined with digital holography and polarization imaging. The detection method of this project can provide theoretical basis and experimental test means for aircraft ice environment warning and atmospheric detection.