Modeling the microwave emission of a moist granular medium

Abstract

Based on the Mie Scattering Theory and the Dense Medium Radiative Transfer (DMRT) Theory, this paper analyze the electromagnetic scattering properties of particles under different humidity and temperature, and discusse the polarization brightness temperature of moist granular layer. The numerical calculation results show that when the particle temperature is over 273 K, the particle humidity has more obviously influence on the electromagnetic scattering properties of sand particles than its temperature. When the temperature is below 273 K, the optical properties of particles are mainly affected by the humidity of particles, and with the increase of humidity, the extinction efficiency of particle shows a trend of increasing initially and decreasing afterwards, and the maximum value appears when the humidity of the wet ice is 0.2. In addition, with the increase of particle temperature and humidity, the microwave brightness temperature of particle layer significantly increases, and its vertical polarization brightness temperature is greater than the horizontal polarization brightness temperature, the maximum difference appears near the observation angle of 55°. However, it is more sensitive to the thickness of sand layer when the observation angle is below 30° and the thickness does not exceed 30 cm.