中文摘要：

借鉴了现阶段二维垄行作物的组分权重确定方法并将其推广到三维城市地表，加上已有的针对城市地表的方法，得到了辐射度方法、水平面投影法、球面投影法和中心投影实验法4种方法。结果表明，当天项角较小时，辐射度方法、球面投影法、中心投影实验法（通过数码像片勾绘统计计算得到组分权重）和水平面投影法都能较为精确地模拟方向亮温的空间分布。

英文摘要：

Directional brightness temperature （DBT） plays an important role in surface energy balance and urban climate. Determination of components＇ proportion is one of the key factors to accurate simulation of DBT. An overview of the main components＇ proportion determination methods used currently on urban surfaces was unfolded and some techniques utilized in row crops were expanded to adapt three dimensional urban targets, achieving radiosity method, horizontal projection method, oblique projection method and center projection method. Comparison between those above mentioned four components＇ proportion determination methods demonstrate that they simulate the spatial distribution of DBT perfectly when the zenith angle is small. The result also shows that it is feasible to compute the components＇ proportion through sketching and calculating on the photograph filmed by a digital camera located near the thermal infrared sensor （center projection method）. However, the horizontal projection method is an exception, which has a low precision corresponding to DBT when the zenith angle increased or differences between components＇ temperature extended to a higher level. Finally, a comparative study was conducted on simulation accuracies and complexities of different methods and some specific recommendations were given for diverse needs.