Comparison of linear and circular polarization in foggy environments at UV-NIR wavelengths

Abstract

This paper investigates the polarization persistence of linear polarization and circular polarization in foggy environments from ultraviolet (UV) to near-infrared (NIR). Using polarization tracking Monte Carlo simulation for varying particle size, wavelength, refractive index, and detection distance, it is shown that linear polarization and circular polarization exhibit different persistence performance. For wet haze of 0.6 μm mean diameter particles, right-handed circular polarization shows better persistence than parallel polarization at wavelengths of 0.36, 0.543 and 1.0 μm. But parallel polarization shows better persistence at wavelengths of 1.55, 2.1 and 2.4 μm. For wet haze of 1.0 μm mean diameter particles, right-handed circular polarization shows better persistence at wavelengths of 0.36, 0.543, 1.0 and 1.55 μm. But parallel polarization shows better persistence at wavelengths of 2.1 and 2.4 μm. For wet haze of 2.0 μm particles and radiation fog and advection fog, right-handed circular polarization shows better persistence at all simulated wavelengths. In short, right-handed circular polarization persists better than parallel polarization in most scenarios, however, with increasing wavelength and decreasing particle size, parallel polarization gradually persists better than right-handed circular polarization. Finally, anisotropy factor for various particle models is used to map the propagation law of right-handed circular polarization and parallel polarization.