静态傅里叶变换超光谱全偏振成像技术

Static Fourier-transform hyperspectral imaging full polarimetry

光谱偏振成像技术是成像光谱技术与偏振成像技术的有机融合,是当前空间光学遥感技术研究的热点和前沿.针对目前光谱偏振成像技术受测量原理、探测模式的限制,普遍需要运动、电控调制等部件,导致体积大,结构复杂,加工装调困难,抗振能力差等问题,我们于2010年在国际上首先提出了一种多信息融合的静态傅里叶变换超光谱全偏振成像方法.本文在此基础上,阐述了新方法的基本原理,给出了具体实现方案.新方案无需运动、电控调制部件,可实现目标图像、光谱、全偏振信息的一体获取.推导出了新方案的调制干涉强度数据表达式及Stokes矢量解调公式,分析了新方法实现光谱、全偏振探测的物理过程.对新方案进行了计算机数值模拟验证,研制了原理验证样机开展了室内、室外验证实验,首次获得了室外推扫光谱图像"数据立方体"和全色全偏振度图像,模拟及实验结果均表明新方案原理正确,技术可行.上述研究为新型空间遥感器的开发提供了基础理论及实践支持.

Spectral imaging and polarimetric imaging are both advanced optical detection techniques. Owing to their wide potential in mil- itary and civil communities, these techniques have rapidly developed within the past two decades and become well-recognized tools in remote sensing. In recent years, these two techniques presented a new trend toward merging into the imaging spectropolarimetry, and make the optical remote sensing tend to multi-dimensional and multi-information fusion. However, in conventional imaging spec- tropolarimeters, rotating polarization elements, electrically controllable components, and microretarder or micropolarizer arrays are typically required. These apparatuses generally suffer from vibration, electrical noise, heat generation, and alignment difficulty. Conse- quently, the incorporation of mechanical components typically increases the complexity and reduces the reliability of the measurement system. To overcome these drawbacks, we propose a novel method of real-time measuring the spectrum, polarization and imaging of scenes with static birefringent crystal elements in 2010. In this paper, the concept and theory of a sensor based on the method are given. With specially aligned static birefringent retarders, different phase factors are modulated into the Stokes vector of incidence light. After passing through a static birefringent interferometer, the spectrally dependent Stokes parameters are distributed into several separated interferogram channels. With corresponding Fourier-transform demodulation, the wavelength-dependent polarization, spectral and 1-D spatial imaging of objects can be completely obtained with a single snapshot. The simulated and experimental demonstration of the sensor are also presented. This research gives a new way for spectropolarimetric imaging measurement, and provides theoretical and practical support for the development of new space remote sensors.