1. Measurements of skylight polarization: a case study in urban region with high-loading aerosol
- Author
-
Lianghai Wu, Jun Zhang, Zhiguo Fan, and Jun Gao
- Subjects
Physics ,Linear polarization ,business.industry ,Forward scatter ,media_common.quotation_subject ,Astrophysics::Instrumentation and Methods for Astrophysics ,Polarimeter ,Skylight ,Polarization (waves) ,Atomic and Molecular Physics, and Optics ,Optics ,Sky ,Electrical and Electronic Engineering ,Rayleigh sky model ,business ,Engineering (miscellaneous) ,Circular polarization ,media_common - Abstract
We investigate skylight polarization patterns in an urban region using our developed full-Stokes imaging polarimeter. A detailed description of our imaging polarimeter and its calibration are given, then, we measure skylight polarization patterns at wavelength λ=488 nm and at solar elevation between -05°10' and +35°42' in the city of Hefei, China. We show that in an urban region with high-loading aerosols: (1) the measured degree of linear polarization reaches the maximum near sunset, and large areas of unpolarized sky exist in the forward sunlight direction close to the Sun; (2) the position of neural points shifts from the local meridian plane and, if compared with a clear sky, alters the symmetrical characteristics of celestial polarization pattern; and (3) the observed circular polarization component is negligible.
- Published
- 2015