Full Polarimetric Emissivity of Vegetation-Covered Soils: Vegetation Structure Effects

In May 1999 the SMOS Earth Explorer Opportunity mission was selected by ESA to provide global soil moisture and sea salinity maps using the MIRAS L-band aperture synthesis interferometric radiometer. At this frequency there is a high dynamic range of the soil moisture signature and surface roughness effects are small, as well as vegetation effects. However, they cannot be neglected at large observation angles or if the vegetation cover is thick and/or dense. In this paper we have carried out a series of simulations to investigate: the effect of the soil moisture content and the vegetation density, the influence of the vegetation structure (number, sizes and orientation of branches and leaves) and the influence of each component (trunk, branches, and leaves) on the four Stokes elements (Tv, Th, U and V).