基于粗糙度形貌数据的花岗岩表面双向反射特性研究

BI-DIRECTIONAL REFLECTANCE PROPERTIES OF GRANITE SURFACE BASED ON ROUGH TOPOGRAPHIC DATA

利用原子力扫描探针显微镜(AFM)获得了花岗岩表面粗糙度形貌数据,分析了该实际表面的形貌特征.在几何光学近似下,根据该实际表面形貌数据采用Monte Carlo法,并考虑表面散射过程中的入射遮蔽及多次散射效应,模拟了实际表面的双向反射分布函数(BRDF).将BRDF模拟值与在入射波长为0.6328μm、不同的入射天顶角和入射平面内条件下实验测得的BRDF值进行比较,结果表明在适当的误差范围内两者符合较好.

Rough topographic data of granite surface were measured by atomic force microscope （ AFM）, and the characteristics of this real surface were analyzed according to the topographic data. In the range of geometric optics approximation, the hi-directional reflectance distribution function （BRDF） of this real surface was modeled by Monte Carlo method based on the surface topographic data, where the shadowing effect of incidence and the multiple reflections were considered. By comparing the modeling results of BRDF with its measured results which were measured at the wavelength of 0.6328μm and at different incidence angles, the results show that there is a reasonable agreement between them within a certain error range.