A synergyc view of L-band active and passive remote sensing of vegetated soil

Abstract

This paper investigates the effects produced by variations of soil moisture and vegetation biomass on the emissivity e and the backscattering coefficient σ° of land surfaces. Several previous works demonstrated that an increase of soil moisture is associated to a decrease of e and a corresponding increase of σ°. Other surface variables, such as soil roughness and vegetation biomass also influence both e and σ°, but in a different way with respect to soil moisture. In a previous paper, it was assumed that an ideal triangle can be traced on the e-σ° plane, with vertexes corresponding to dry soil, wet soil and dense vegetation conditions, respectively. In this paper, this assumption is tested using passive and active signatures collected by SMOS and ALOS-PALSAR instruments, respectively, over various kinds of surfaces.