Polarimetric Remote Sensing in O2 A and B Bands: Sensitivity Study and Information Content Analysis for Vertical Profile of Aerosols

Abstract:

High spectral intensity and polarization measurements within gaseous absorption bands can be used to retrieve the vertical distribution of the absorbing gases, clouds and aerosols. Polarization measurements offer additional information about the absorbers and scatterers. However, most of such kind of retrievals ignore polarization effects of the reflected radiation. In this study, we focus our attention on both the O₂ A and B bands to investigate the effects of various aerosols on the behavior of the degree of linear polarization (DOLP) of light in the O₂ A and B bands under different surface conditions. The Unified Linearized Vector Radiative Transfer Model (UNL-VRTM) is used to simulate the Stokes 4-vector elements and their Jacobians with respect to the aerosol optical and physical parameters. In order to select the most sensitive wavelengths, the concepts of ‘Degree of Freedom for Signal (DFS)’ are used to examine the sensitivities of individual wavelength in both O₂ A and B bands. Our results indicate that polarization of light contains more aerosol vertical distribution information than that of intensity. And combining both O₂ A and B bands, less number of channels are required used to retrieve the vertical distribution information.