Sky polarization pattern under multi-layer environment of atmosphere and sea fog

Abstract

The vertical polarization distribution pattern of sea fog multilayer media and skylight in the atmosphere is explored. To change the complicated maritime environment, the simplified double layer structure of the atmosphere and sea fog is employed, and the scattering coefficients of the uniform atmosphere and sea fog medium are derived using the Rayleigh and Mie scattering methods, respectively. Using the adding-doubling method (RT3) based on the vector radiation transmission equation, the transmission of radiation between the two layers of the medium is calculated to obtain the polarization distribution conditions of skylight, and the variation tendency of the polarization characteristics observed from the ground is studied for the downwelling radiation of sea fog on the meridian of the Sun. An indoor sea fog setting was employed to perform the polarization transmission test, and the relationship between humidity, light intensity transmittance, and polarization degree was explored. The data suggest that the Sun’s position gives the lowest degree of polarization (DOP), and that the maximum value is obtained when the angle between the solar altitude angle and the observed altitude angle is 90°. Short wavelength lasers have a higher influence on optical transmittance than long wavelength lasers do when humidity levels increase. The circular polarization effect of long wavelength laser is better in damp surroundings.

Study of multispectral polarization imaging in sea fog environment

“…Due to the serious scattering effect of chaotic media such as tiny particles and soluble organic matter suspended in sea fog on light waves, light-intensity information is scattered and absorbed by aerosol particles with a high concentration of sea salt suspended over the sea surface during atmospheric transmission, resulting in faster light attenuation during transmission, making the background scattered light superimposed on the target light to form noise [1][2][3]. Therefore, maritime scenes are more susceptible to chaotic environments than non-maritime scenes, making imaging appear with more complex target backgrounds, blurred effects, large coverage of detailed information, and a significant decrease in contrast [4][5][6], which directly affects the accuracy of analysis and judgment of the imaging content. Therefore, along with the increasing attention and more rapid development of spectral polarization imaging technology, the technology has continued to advance the development of imaging technology, which is important for the study of clear target imaging, images containing a high amount of information, and high imaging contrast and clarity.…”

Experimental study on atmospheric polarization characteristics measurement with different observation angles and wavelengths

“…A computational analysis model has been proposed by Xin Wang et al to simulate variable astronomical polarization patterns [3] . The sky's polarization patterns in multi-layered atmospheres and sea fog environments have been explored by Qiang Fu et al [4] , while the traditional analytical model has been improved by Tian Yang et al to make simulation results more consistent with actual measurements [5] . *leibing_2000@nudt.edu.…”