地表温度是地质学、水文学和陆面过程研究中的重要参数。由于地表的三维结构和异质性,大部分不同类型陆地表面均存在不同程度热辐射方向性现象。总结了基于真实结构的地表热辐射方向性计算机模型研究进展,归纳了真实结构模型中蒙特卡罗光线追踪法和辐射度方法的理论基础,阐明了两种方法的区别和联系,并从理论和物理意义上分别推导和阐释了其与几何光学模型及辐射传输模型的关系,指出了真实结构模型在算法效率、非同温系统蒙特卡罗模拟、参数获取、模型反演和应用等方面存在的主要问题,并展望了其在未来的发展趋势。
Land surface temperature is one of the most important parameters in geology, hydrology and land surface process models. However, thermal anisotropy lies in almost all types of land surfaces due to their three dimensionality and heterogeneity. Based on realistic structure model, some progresses of computer simulation about land surface thermal anisotropy in recent years have been summarized. The theoretical basis of Monte Carlo Ray Tracing (MCRT) and radiosity was generalized and various types of approaches were reviewed simultaneously. Both of them are widely used in many fields, including the estimation of directional emissivity and directional brightness temperature (DBT), validating other common used models and combining energy balance model with computer simulation models. The similarities and differences between MCRT and radiosity method were also clarified, in which time complexities of these two algorithms are both high, and in addition, the backward-MCRT and radiosity are independent on view direction while the forward-MCRT is on the opposite side. MCRT is applicable to specular-specular and specular-diffuse surface reflection, while diffuse surfaces need radiosity methods. Statistical geometrical data of the objects is optional for MCRT while realistic stcucture is necessary for radiosity. The realistic model was then compared with geometrical optics and transfer radiation models. Theoretical deri- vation indicates that the computer simulation model is almost equivalent to geometrical optics model without considering multi-scattering between objects. For transfer radiation models, on the other hand, thermal radiation transfer equation is fit for being applied to mixed dispersion media, while being suitable for inter-planes, the radiosity integral equation is on the basis of radiation balance of ' micro-plane'. Finally, some inherent defects of computer simulation model, consisting of time efficiency, MCRT in non-isothermal surfaces ,parameters acquisition, inversion and application have b