Modeling Backscattering from Leafy Vegetation: the Incoherent and Coherent Approaches

The availability of a considerable amount of Synthetic Aperture Radar data, obtained from airborne and spacecraft systems, has stimulated significant research for the purposes of interpreting backscattering data and investigating the potential of radar remote sensing for various applications. Vegetation has been one of the most studied subjects; however, much of the work has been carried out in forestry while less attention has been paid to agricultural crops. Experimental research has demonstrated that the microwave backscattering coefficient is sensitive to crop biomass, and is affected by the shape and dimensions of plant constituents, so that, different crop types with the same biomass may have different values of backscatttering. For example, on "broad leaf" crops, such as sunflower, backscattering increases with an increase in the biomass, as it is typical of media in which scattering is dominant, whereas on "narrow leaf"plants, such as wheat, the trend is flat or decreasing, denoting a major contribution of absorption [1,2].