INVESTIGATION ON THE VALIDITY REGION OF ANALYTICAL MODELS SIMULATING SCATTERING FROM VEGETATION ELEMENTS

Electromagnetic models, able to simulate scattering from vegetation, are widely used in the remote sensing community in order to interpret space-borne or air-borne SAR data and to develop algorithms capable to derive from them bio-physical quantities (i.e. biomass, tree height, etc.). Most of the models consider the vegetation as an ensemble of simple elements (cylinders, discs) for representing the different parts which compose the plant (e. g. trunk, branches, leaves, etc.). Specific analytical models able to describe the scattering form this elements were developed in the past but theirs validity ranges in terms of frequency or elements dimensions were not yet fully investigated. A comparison between analytical models and a numerical full wave model for cylinders, elliptical and spherical discs at different frequencies in the 1.5 - 20 GHz range is presented here.