基于多角度偏振相机的城市典型地物双向反射特性研究

基于高空间分辨率多角度偏振相机(directional polarimetric camera,DPC)获取的中国珠江三角地区典型地表多角度航空数据,在航空尺度上反演得到城市区域四种典型地物的三种半经验双向反射率(bidirectional reflectance distribution function,BRDF)模型的参数,并对模型精度进行分析.结果表明,三种半经验BRDF模型对多角度反射率数据都有较好的拟合能力,其中,Ross-Li模型对森林类型的拟合误差最小,Ross-Roujean模型对裸土类型的拟合误差最小,RPV模型对城市和灌木类型的拟合误差最小.在此基础上,重点分析了四种城市典型地物高空间分辨率的双向反射特性,研究发现,不同地物的反射率存在差别,但整体趋势都随着散射角的变大而变大.城市区域典型地物类型双向反射特性的研究,将为基于遥感数据探测地表和大气物理光学参数提供理论支持.

Research on the bidirectional reflectance of typical urban surface types measured by the directional polarimetric camera

This paper deals with the retrieving of the bidirectional reflectance distribution functions (BRDFs) of the distinct urban cover in the Pearl River Delta (PRD) region employing the high-spatial-resolution multi-angle polarized measurements made by the directional polarimetric camera (DPC). The results show that three BRDF models (RPV, Ross-Roujean and Ross-Li) describe the DPC measurements well. Forest is best fitted by Ross-Li and bare soil is best fitted by Ross-Roujean. Urban and shrub are best fitted by RPV. The results demonstrate that the reflectances of different types of surfaces are different and increase with the increase of scattering angle. The basic theory of investigating surface properties using multi-angle measurements is proposed.