高光谱对地观测激光雷达波段选择机理与方法研究

LiDAR remote sensing for objects detection has great vertical spatial resolution; however, the lack of backscatter spectral information limits its ability to distinguish the properties of object feature. Hyperspectral LiDAR which combined the ability of high vertical resolution and spectral resolution is the new trends of LiDAR detection for earth observation. However, due to the band selection result and the resolve method of high spectral resolution is not implemented in optimization, most of the reception bands in a non-sensitive or related bands which resulting in band redundancy, so it is hard to exploit the performance of high resolution detection of Hyperspectral LiDAR. This project proposed to resolve the optimization detection problem of hyperspectral LiDAR in order to improve its capability of high resolution detection. We focused on the research of optima wavelength and band width selection method; meanwhile, we would carry out grating segmented design and apply high sensitivity Geiger mode APD linear array for weak signal detection based on the theoretical of band selection research. According to the research through this project, we expected to achieve high spectral and high spatial resolution by a LiDAR sensor which will play a more important role in the earth observation.

激光雷达对地探测技术具有很高的垂直空间分辨能力，但回波光谱信息的欠缺限制了其对地物物性的判别能力。高光谱激光雷达结合垂直空间和高光谱分辨的探测能力，是激光雷达对地观测技术发展的趋势。现有高光谱对地观测激光雷达技术在激光回波波段选择和高光谱分辨探测等方面没有实现最优化，致使大部分接收波段处于非敏感或关联波段，造成波段冗余和光谱分辨较低，难以体现高光谱激光雷达的高分辨探测性能。本项目针对高光谱激光雷达发展面临的最优化探测问题，开展接收波段特征选择研究，确定接收通道的最优中心波长和带宽，解决敏感波段光谱分辨不足和非敏感波段光谱冗余的问题；在此基础上，采用光栅分段分光设计和高灵敏度的Geiger模式APD线阵探测，实现对敏感波段的高光谱分光优化，解决高光谱波段的弱信号探测问题。通过本项目探索研究，有望在一台激光雷达传感器上实现高光谱和高空间分辨的探测能力，在对地观测中发挥更重要作用。

现有激光雷达遥感技术具有高三维空间分辨能力，但回波光谱信息的欠缺限制了其对地物物性的判别能力。本项目提出开展一种基于超连续谱激光光源的高光谱地物探测激光雷达基础研究，期望解决激光雷达光谱分辨不足及高空间与高光谱分辨同步观测问题。项目研究中，首先开展高光谱激光雷达波段选择机理与方法研究，在此基础上，初步建立了高光谱激光雷达原理、技术和应用的相关理论基础；在针对植被探测的高光谱激光雷达波段选择理论、超连续谱激光光源能谱分布设计和功率测试、多通道光栅分光优化设计和探测、高光谱激光回波光谱分析等方面进行了深入的研究。以理论为指导，完成了高光谱激光雷达实验样机的研制。该系统可同时获取地物的空间和物性信息。而且，由于采用激光主动探测，还具有全天时工作能力。通过本项目研究，为推动激光雷达遥感技术从现有的单波长向高光谱方向发展打下良好的原理与技术基础。