光波在云层中的传输特性研究

Research on transmission characteristic of light in cloud

云层的传输特性主要由透射率和偏振特性两部分组成。太阳光经过云层传输,一方面太阳光的辐射能量会衰减;另一方面其自身携带的偏振信息也会发生改变。该文采用蒙特卡罗方法模拟仿真了太阳光在云层中的散射过程,得到了水云和冰云在1.5μm、2.5μm、3.3μm波长入射光下的传输模型,并在此基础上分析研究了不同云层的传输特性。结果表明在同种波段下,水云对太阳光的衰减作用明显要高于冰云,并且在λ=3.3μm时,衰减最大;而对于云层偏振特性的研究发现在同种入射光波段下,冰云的消偏作用要明显高于水云,并且随着入射光波长的增加,云的消偏作用也越来越明显,在λ=1.5μm和λ=2.5μm时,变化较小,但在λ=3.3μm时变化较大。

The transmission characteristics of the cloud mainly include transmittance and polarization property.After transporting through the cloud,the radiant energy of the light will be attenuated,more important is that its own carrying polarization information will be changed.In this paper,the scattering process of sunlight in the cloud using the method of Monte Carlo is simulated,the transmission model of water cloud and ice cloud under the wavelength of incident light with 1.5 μm,2.5 μm,3.3 μm is obtained.On this basis the transmission characteristic of different cloud is analyzed.The results show that in the same kind of band the attenuation effect of water cloud on sunlight is significantly higher than that of ice cloud.The study on polarization properties of cloud proves that the depolarization effect of ice cloud is significantly higher than that of water cloud in the same kind band of incident light,and the depolarization of the cloud becomes more evident with the increase of the wavelength.