Modeling and Analysis of Microwave Emission from Multiscale Soil Surface

Abstract

This paper analyzes the microwave emission from the multiscale soil surface, characterized by a modulated correlation function. The modulation ratio, defined as the ratio of baseband correlation length and modulated length, determines the degree of multiscale roughness. We examine the frequency and look angle response of emission to the multiscale roughness. The results indicate that, as the modulation ratio increases, the H polarized emissivity increases more obviously. By comparison, the V polarized emissivity is less sensitive to the multiscale effect. Besides, both the H and V polarized emissivities, given rise from the modulation effect, are significantly enhanced at small and moderate look angles. Results suggest that the multiscale effect may be negligible when the look angles are around 45°~50° at V polarization. The results in this study may provide a promising clue to decouple the multiscale effects, thus leading to more reliable emission observations.