扩展目标光学特性的理论分析与研究

利用双向反射分布函数经验公式推导出激光主动照明条件下的目标反射截面表达式，给出了目标反射截面的一种近似计算方法，基于该方法计算了圆锥体目标反射截面。利用固体激光器和CMOS相机搭建实验系统,实际测量了目标反射截面随入射角度和不同目标体等参数变化时的变化情况，实验系统及数据同提出的方法计算得到的结果基本一致。结果表明，目标形状相同，入射角小于45时，目标反射截面随着无涂层、白色油漆、灰色油漆逐渐变小，大于45时白色油漆涂层目标反射截面最大；在目标表面特性相同的时候，目标反射截面随圆板、圆柱、圆锥渐次减小。

Theoretic analysis and experimental study on optical characteristics of extended targets

Based on the target reflection section defined by the bidirectional reflectance distribution function, a method of approximate calculation and analysis of the cones and plate’s reflection section in laser-illuminated condition put forward. With the method, the reflection section of cone was calculated and analyzed. An experimental platform was established with Nd:YAG laser and CMOS camera, through which the experimental research is carried out on the target characteristics under the condition of laser lighting. The experimental result of the reflection section and its theoretically calculated result were in agreement with each other. The results show that, among different targets of the same shape with no paint, white paint and gray paint layer, if the incidence angle is less than 45°, the reflection section gradually decreases, otherwise, the reflection cross section of the target with white paint layer is greater than others. Among plate, cylinder and cone shaped targets with the same paint layer, the reflection cross section diminishes by turns.