行播作物是介于离散植被和连续植被的一种典型植被类型,Kimes等人从纯几何光学角度研究了行结构的热辐射方向性,但视行结构为“箱型”实体,不考虑作物组分间的孔隙因素与大气下行辐射效应.在太阳光照方向和观测方向上同时考虑了作物间的孔隙率因素,根据离散植被孔隙率模型和连续植被的交相关概率思想,分别从行结构中的无遮挡、单向投影和双向重叠投影3个方面出发,建立行结构孔隙率模型.模型应用体系总有效发射率概念,解决了不同天顶角时非同温目标的环境辐射效应计算问题.经与实际观测结果对比,孔隙率模型比Kimes模型能更准确地描述行结构热辐射方向性.由于考虑了光照方向和观测方向的交相关关系,孔隙率模型可以解释热辐射中的热点现象. Row crop is a typical type of vegetation between discrete vegetation and continuous vegetation. Kimes et al. Studied the thermal radiation directivity of row structure from the perspective of purely geometric optics. However, the row structure is a “box-type” entity, irrespective of crop The pore space between components and the downward radiative effect in the atmosphere.According to the porosity of the crop in the direction of the sun’s illumination and the observation direction, according to the idea of ​​the correlation between the discrete vegetation porosity model and the continuous vegetation, Unidirectional projection and bidirectional overlapping projection, the model of row structure porosity is established.The model applies the concept of total effective emissivity of the system to solve the calculation problem of environmental radiation effect of non-isothermal target with different zenith angles. Compared with the actual observation results, the porosity model can describe the thermal radiation direction more accurately than the Kimes model.The porosity model can explain the hot phenomenon in the thermal radiation, considering the cross correlation between the illumination direction and the observation direction.