微型、噪声免疫、快照式全Stokes偏振光谱光场摄像技术及定标研究

Snapshot imaging spectropolarimetry is a cutting-edge remote sensing technique for the real-time acquisition of multimode multi-dimensional optical information such as the state of polarization, spectral distribution, and spatial morphology of object. It has attractive application in the field of space remote sensing since it can capture dynamic object and has immunity to environment perturbation. However, it is hard to achieve a system simultaneously with compact, miniature and real-time display features, because the existing snapshot techniques usually need huge volume for optical encoding, or massive computation for decoding, or both. In this project, an orthogonally spatial modulation technique of polarization and spectrum will be integrated into the light-field imaging principle configuration with a single area-array detector. Then an innovative snapshot full-Stokes polarization spectral light field videography with the characteristic of noise immunity will be developed, and the correlation rules between the light-field imaging array and full-Stokes polarization spectral information will be explored. We attempt to reduce the complexity of the encoding/decoding and simultaneously achieve a compact, miniature and real-time display system. At the same time, we try to build a spectral polarization state generator with the tunable degree of polarization for calibrating and characterizing system. The basic issues of full-Stokes polarization spectral light-field videography will be analyzed in this project. The principles and theories on the light-field information modulation, the encoding of multi-mode multi-dimensional information into a single area-array detector, the reconstruction and recognition of multi-mode multi-dimensional information, and the calibration and characterization of system performance will be studied theoretically and experimentally. The achievements of the project will provide basic theories and techniques for the space optical remote sensing with polarization spectral imaging.

快照式全Stokes偏振光谱成像是一项实时获取目标偏振态、光谱分布、空间形貌等多模态多维光学信息的前沿遥感探测技术，适用于捕捉动态目标，免疫环境扰动，在空间光学遥感领域具有诱人应用前景。但现有技术存在多维信息编码结构体大、解码算法复杂繁重等问题，难以同时实现紧凑微型化和实时显示。本项目拟在基于单面阵探测器的光场成像原理结构基础上，融入偏振与光谱正交的空间调制方法，创建一种具有噪声免疫特性的快照式全Stokes偏振光谱光场摄像技术，探索光场像点阵列与全偏振光谱信息之间联系规律，降低编/解码复杂度，实现紧凑微型化和实时显示，并发展一种光谱偏振度可调的偏振态发生器用于标定系统。拟开展全偏振光谱光场摄像的基础研究，针对多模态多维信息的光场调制、同时编码于单面阵探测器、重构与识别，及系统定标与性能表征等基础技术的机理问题进行理论分析和实验研究，为基于偏振光谱成像的空间光学遥感奠定理论基础和技术手段。

快照式偏振光谱成像是一项实时获取目标偏振态、光谱分布、空间形貌等多模态多维光学信息的前沿遥感探测技术，适用于捕捉动态目标，免疫环境扰动，在空间光学遥感领域具有诱人应用前景。但现有技术存在多维信息编码结构体大、解码算法复杂繁重等问题，难以同时实现紧凑微型化和实时显示。本项目探索出了一种适于光场成像原理结构的偏振光谱调制方法，创建了多模态多维信息同时编码于单个二维面阵探测器的理论模型，并形成了一套具有噪声免疫特性的快照式Stokes偏振光谱光场摄像技术，及其配套的定标与数据重构技术。基于上述理论，共研制出了3套可获取多维信息的原理样机：第一套是紧凑微型、噪声免疫、快照式消色差全Stokes偏振成像仪（ASSIP），及其配套的定标装置和算法软件，实现了宽谱段偏振图像的动态实时精确获取与重建，偏振度灵敏度达0.4%， 相对偏振精度达3.6%。第二套是基于焦平面渐变滤光片的紧凑微型、快照式光学复制与重绘成像光谱仪（ORRIS），及其配套的定标装置和算法软件，实现了可见到近红外宽谱段高光谱图像的动态实时获取与重建。第三套是基于焦平面渐变滤光片的紧凑微型、快照式光学复制与重绘成像光谱偏振仪（ORRISp），及其配套的定标装置和算法软件，实现了可见光波段的偏振光谱图像的动态实时获取。ORRISp能以探测器固有视频速率拍摄二维场景的偏振光谱图像，波段范围在450nm-750nm范围，光谱分辨率达56个波段以上，视觉范围±5.8°，空间分辨率达400*400个像元以上，并具备支持性能重构的转换配置。基于ORRISp原理，提出了一种基于单通道偏振调制的快照式偏振光散射光谱技术，具有实时调节特性，非常适于胃肠道的内窥早癌诊断应用。为了开发系统方案的实用性，研发构建了一系列用于偏振光谱图像的目标检测和识别算法，并应用于高光谱图像分类、高光谱图像变化检测、偏振增强聚类等任务。