Research On Polarized Characteristics Of Scattering Skylight For The Bionic Navigation

In these years, the polarized characteristics of scattering skylight have been the subject of numerous theoretical and experimental investigations. The clear sky has a characteristic polarization distribution. Biologists' research shows that the desert ant can navigate with the pattern of the skylight polarization. Their vision nervous systems are sensitive with angle of scattering skylight polarization. It's very important to do the measurement and analysis on the polarized characteristics and distribution pattern of scattering skylight.The Rayleigh scattering theory and physics foundation of atmosphere optics is presented first in this paper. After that, we introduce the typical methods which are used to describe the polarization state of light beam and their relation. We put forward the measurement project with Mueller matrix and Stokes vector. Hardware configuration of the measuring system on scattering skylight polarization is established. Thereafter, software design of the measuring system is finished in the VC environment with C language and OpenGL application. This software can carry out the data pick-up, classification, processing, and conservation of the measurements. Furthermore, the software can display not only the radiance intensity, degree and angle of polarization, Stokes vectors, measurement time, wavelength, and atmosphere condition, but also the distribution pattern of scattering skylight polarization in the full-sky.Specifications of the measurement system are obtained after calibration. And then we do measurements with the measuring system through the Zenith point, solar vertical plane, and full-sky. The distribution pattern and polarized characteristics of scattering skylight are acquired in the spectral range from 400nm to 750nm. In addition, the measurement results demonstrate that our measuring system can obtain the radiance intensity, degree and angle of polarization, and wavelength availably.With analysis of the measurement results, we verify the relation between Rayleigh theory, solar elevation angle, scattering angle, wavelength and polarized characteristics of scattering skylight. The differences between actual and theoretic distribution are concluded as well. Furthermore, we discuss limited condition and feasibility of the polarized characteristics of scattering skylight for the Bionic Navigation.