Patterns of Skylight Polarization at Different Atmospheric Conditions

摘要

A skylight polarization measurement system has been designed,and the measurements of skylight polarized radiance distribution have been performed at different atmospheric conditions. The patterns of skylight polarization measured at four kinds of atmospheric conditions at the spectral range 450～475 nm are presented. It is obvious that qualitatively the patterns of skylight polarization in sunny skies are in agreement with Rayleigh model. The stronger atmospheric turbidity, the greater disturbance to the patterns of skylight polarization appears in the atmosphere. The degree of the skylight polarization P and the angle of the skylight polarization χ are the greatest in the clear sky. However, some meteorologic factors disturb the patterns of skylight polarization more or less. Cloud layer, dust, etc decrease the greatest P and corresponding χ of skylight polarization at different atmospheric conditions. In addition, the cloudy sky has terrible patterns of skylight polarization because it is overclouded and the sunlight is occluded completely.