Refractive index impacts on polarized signals from a homogeneous Rayleigh scattering medium exposed to oblique irradiation

Abstract

Refractive index mismatched boundaries commonly occur in many polarimetric observations However, the refractive index effect on the polarization signals from a scattering medium has been rarely investigated and poorly understood. Thus, the polarization signals from a scattering medium with mismatched boundaries are expected to be accurately captured to investigate refractive index effects. In this work, the polarized radiative transfer in a homogeneous Rayleigh scattering slab medium with a refractive index bigger than its surrounding is numerically solved. By fixing the refractive index of the background and the composition of the scatterers in the scattering medium, we studied the refractive index impacts on the polarization signals by varying the refractive index of the Rayleigh scattering medium. Results show that for the media with different refractive indices, the reflected and transmitted radiation intensity is found to diminish monotonically, while the maximum degree of polarization (DoP) decreases at first and then increases versus the refractive index. The refractive-index-dependent polarization signals presented in this work are expected to have guiding implications for target probing, such as water detection from the atmosphere.