植被遥感辐射传输建模中的异质性研究进展

Recent progresses on the remote sensing radiative transfer modeling over heterogeneous vegetation canopy

遥感辐射传输建模是在研究电磁波与地物相互作用机理的基础上,建立遥感观测信号与地物属性、地物结构和观测几何等参量之间定量关系的模型,是理解遥感观测信号和反演地表参量的理论基础。近年来空间异质性问题引起了定量遥感领域的高度关注,高分辨率卫星及激光雷达等数据的日益丰富给研究空间异质性提供了有力支撑。在异质性植被场景遥感辐射传输建模过程中,像元内部的组分比例、3维结构、空间格局以及端元边界处的阴影效应与散射过程等方面是需要重点考虑的因素。本文在总结非均质地表空间异质性描述的基础上,分别总结了植被二向性反射与热红外辐射方向性建模研究的发展历程,以及非均质地表植被遥感建模研究的最新进展,并指出了地表遥感建模中研究异质性问题的发展方向。

Radiative transfer models establish the quantitative relationship between remote sensing signals and physical parameters, includ- ing the object properties, the object structures and the observation geometries, on the understanding of the interactions of the electromagnet- ic wave and the objects. They serve as the theoretical basis for the interpretation of the remote sensing signals and the retrieval of surface parameters. Recently spatial heterogeneity has drawn widespread attention in the field of quantitative remote sensing. The increasing high resolution imagery and LiDAR data provide a strong support for the consideration of heterogeneity. For the radiative transfer modeling pro- cess over heterogeneous vegetation scenarios, the component area ratio, the 3D structure and the distribution pattern within the pixel, and the shadowing and scattering effects near the boundary, are important factors that should be considered. The recent progresses on the VIS/NIR BRDF and the TIR directional emission modeling over heterogeneous land surfaces are introduced, respectively. The key scientific issues and future development directions of heterogeneous vegetation canopy modeling are proposed at last.