粗糙目标样片光谱双向反射分布函数的实验测量及其建模

实验测量了紫红色和白色涂漆板在400～780 nm内的光谱双向反射分布函数(光谱BRDF),分析了光谱双向反射分布函数随波长及散射角的变化趋势与目标样片光学特性的关系.应用改进的粒子群算法,结合双向反射分布函数五参量模型,获得了测量光谱范围内各波长(间隔1 nm)对应的共381组五参量值.利用五参量模型计算了目标样片的光谱双向反射分布函数及其方向半球反射率(DHR),并与实验测量数据相比较,两者吻合良好,表明目标光谱双向反射分布函数建模方法与结果的可行性和可靠性.目标样片的光谱双向反射分布函数可以用来研究目标的光谱散射特性,对目标的探测、跟踪、识别和特征提取等具有重要的应用价值.

Experimental Measurement and Statistical Modeling of Spectral Bidirectional Reflectance Distribution Function of Rough Target Samples

The spectral bidirectional reflectance distribution function (spectral BRDF) of mauve and white painted plate are measured in the visible spectrum (400～780 nm). The relationship between variation of spectral BRDF with wavelength and scattering angle and optical characteristics of the measured samples is discussed. With five-parameter model of BRDF and the modified particle swarm optimization (PSO) algorithm, the optimum parameters of the model at each wavelength in the measured spectrum are retrieved at intervals of 1 nm. Spectral BRDF and directional hemisphere reflectance (DHR) of samples calculated with the model are in good agreement with the measured data, which indicates that the means and result of spectral BRDF modeling are doable and reliable. Spectral BRDF of target samples can be used in the research of spectral scattering of objects, which is of great value to the detection, tracking and identification of objects.