利用反射函数、放射系数描述激光雷达目标特性具有重要意义，文中就激光雷达目标特性双向反射函数，双向反射系数，方向半球反射系数，后向反射率等各量的定义进行了论述，并利用红外辐射的基本原理推出了函数与系数，系数与系数的相互关系，得到了一般情况下双向反射函数与双向反射系数，方向半球反射系数与双向反射函数，方向半球反射系数与后向反射率的相互关系，解释了各量在满足一定条件下存在着一种π关系，提出了利用这种相互关系可从某一个量而推出其它各量的结论 The use of reflection function and emissivity to describe the target characteristics of laser radar is of great significance. The definitions of bi-directional reflection function, birefringence coefficient, direction-hemispherical reflection coefficient and retroreflectivity of laser radar target are described in this paper. The basic principle of infrared radiation introduces the correlation between function and coefficient, coefficient and coefficient. The relationship between bidirectional reflection function and bidirectional reflection coefficient, direction-hemispherical reflection coefficient and bidirectional reflection function, direction-hemispherical reflection coefficient and retroreflection Rate of the relationship between the explanation of the amount of certain conditions in the existence of a π relationship exists, the use of this relationship can be introduced from a certain amount of other conclusions and conclusions