提出一种高光谱成像激光雷达系统的光学结构设计,并对系统的光学辐射定标方法进行研究。利用单色仪对出射光的精细扫描,确定高光谱成像雷达每个探测通道的带宽和中心波长。根据高光谱成像激光雷达方程,在实验室定标过程中,不考虑大气对定标的影响,得到系统每一个通道的定标系数。系统定标过程中合成不确定度为0.87%,扩展不确定度(k=2)为1.73%。最后对超连续谱高重复频率激光器出射的脉冲能量进行监测,使该高光谱激光雷达在机载飞行过程中,依据探测器输出的回波信号强度信息,能够实时得到地物的反射光谱信息,进而实现高精度地形获取和地表超精细分类。

In this study, an optical structure design and optical radiometric-calibration method for a hyperspectral-imaging lidar system are proposed. Using the proposed method, the central wavelength and bandwidth of each receiving channel were directly determined using a scanning monochromator. The system-calibration coefficients of each channel were measured in the laboratory using the hyperspectral-image lidar equation and excluding the influence of atmosphere extinction. Simulation results show that the synthetic uncertainty is 0.87% and the extended uncertainty (k=2) is 1.73%. Furthermore, a novel technique was used to monitor the emitted laser-pulse power in real time during the flight experiment. Based on echo-signal intensity information from the detector, the hyperspectral reflectance of the earth's surface can be accurately retrieved, and the high-precision terrain acquisition and super-fine surface classification can be realized.