全天空散射光场全矢量偏振成像导航传感器的优化设计与补偿方法研究

At present, the two-dimensional Stokes-Mueller polarization algebra has been widely used to analyze the polarization characteristics of all-sky scattering light field and the calibration of polarimetric navigation sensors (PNS). Strictly speaking, at any time, the vibration direction and propagation direction of sky scattering light field are always in a random state. Therefore, the research on the polarization characteristics of all-sky scattering light field should be considered in a three-dimensional (3D) space. Based on the 3D coherency matrix, this study intends to propose a 3D polarization vector tracing transmission algebra to quantify the relationship between each parameter and the whole PNS’s polarization performance. Then, the global optimization design method of PNS is derived. Furthermore, by utilizing the between the non-uniform polarization mode of RPC and the dual LCVR’s matching modulation of retardance and fast axis orientation, the full-vector polarization recognition detection function is implemented on each imaging pixel. Finally, the PNS can have the higher full-vector polarization sensitivity and measurement accuracy of polarization characteristics for all-sky scattering light field under complex weather conditions. It is especially significant for providing a strong theoretical support for the information acquisition of PNS, and promoting the practical process of the biomimetic navigation and positioning technology.

目前，普遍采用二维Stokes-Mueller偏振算法分析天空散射偏振特性及导航传感器的偏振定标，严格地讲，任意时刻，天空散射光场电矢量的振动方向与传播方向始终处于随机状态，其偏振特性的探究应出于三维考虑。本项目拟基于三维相干矩阵提出三维偏振矢量追迹传输理论模型，定量追迹天空散射光场在光学器件/系统中的偏振传输特性，分析各参数与系统偏振特性之间的解析关系，进而指导系统偏振特性的优化设计。结合PI-LCOS-SLM偏振补偿方法对系统的残余偏振特性进行高精度实时补偿，实现导航传感器偏振性能的全局优化设计。深入研究RPC的非均匀偏振模式与双LCVR相位延迟和快轴方位角之间的匹配调制关系，在各个像素点上实现全矢量偏振识别探测功能，使导航传感器能够在复杂天气条件下仍具有较高偏振敏感度和观测精度，为仿生偏振导航信息获取提供强有力的理论支撑，促进仿生偏振自主导航定位技术的实用化进程。

本项目从如何提高全天空偏振模式观测精度的角度入手，开展了全天空散射光场全矢量偏振导航传感器系统优化设计与补偿方法研究。首先，基于三维相干矩阵准确描述了天空散射偏振光场，在此基础之上建立三维偏振矢量传输的理论模型，实现了定量追迹天空散射光场在光学介质/系统中的偏振演变特性；其次，从偏振矢量光线追迹的角度，利用所提出的三维偏振矢量传输模型对偏振成像导航传感器进行全矢量化，分析各个参数与系统偏振特性之间的定量关系，完成了对成像导航传感器核心部件——微透镜阵列的保偏设计,并基于Stokes矢量对所设计的偏振成像导航传感器进行了误差分析与优化补偿；最后，深入研究了RPC与双LCVR二者之间的匹配调制模式，实现了对入射偏振光场椭率角[-π/4, π/4]和方位角[-π/2, π/2]的全量程任意调控，在各个像素点上均实现了全矢量偏振成像识别探测功能，使其能够在复杂天气条件下仍具备有较高的偏振敏感度，进而保证导航传感器对全天空散射偏振的观测精度。