多次散射因素影响下天空偏振光模式的解析模型  

An analytical model for skylight polarization pattern with multiple scattering

作　　者：吴良海[1] 张骏[1] 范之国[1] 高隽[1] 

机构地区：[1]合肥工业大学,计算机与信息学院,合肥230009

出　　处：《物理学报》2014年第11期210-217,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:61271121,61102153)资助的课题~~

摘　　要：为了解决天空偏振光模式的描述问题,从经典的瑞利散射模型出发,考虑大气粒子尤其是气溶胶粒子的多次散射特性,构建了一种天空偏振光模式的解析模型.首先分析大气分子的瑞利散射,并结合Perez光强分布模型描述光强分布,而后考虑二次散射因素,分析不同尺度不同组分典型粒子的散射相位函数,根据其角度分布特征,解决二次散射积分的求解问题,最终得到本模型.仿真实验表明,与瑞利散射模型相比,本模型能够解决实际天空中存在的中性点的描述问题.与晴朗天气下不同时刻实际测量结果之间的对比进一步说明,本模型不仅可以定性地描述实际天空中偏振光模式的角度变化趋势、中性点以及对称性等重要特征,而且具体数值与实际分布之间的符合程度要优于单次散射模型,其中偏振度的相似度最高可以达到75%左右.To solve the issues in the modeling of skylight polarization, we build a new analytical model of skylight polarization patterns, which is based on the classic Rayleigh scattering and takes into consideration the multiple scattering properties of atmospheric particles, especially the aerosol. In this paper, we first build the model by the combination of single Rayleigh scattering and classic Perez sky models. Then we analyze the influence of secondary scattering by solving scattering phase function of different particle sizes and components of aerosol in OPAC data. Finally, the integral function for secondary scattering is simplified with the preferences of scattering phase function in forward direction. Compared with the Rayleigh model, our model can depict the existence of neutral points in the sky. The comparisons between our model and the measured results of clear sky further validate that the model not only exhibits characters of measured skylight polarization, such as the variation＇ tendency, neutral points and the pattern symmetry, but also consists with the acquired values than the single scattering model; for example, the degree of similarity of polarization can be up to 75%.

关 键 词：偏振光 多次散射 解析模型 中性点 

分 类 号：O436.3[机械工程—光学工程]