Sensitivity of Multi-Temporal L-Band Radar Backscattering Power to Soil Moisture for Two Crops with Contrasting Features [* Cross-Reference *]

Since crop plants involve dielectric elements of complex shapes, sizes and orientations, a number of scattering mechanisms combine together to yield the microwave backscatter response. This paper aims at assessing soil moisture variations through a canopy imaged by an airborne Synthetic Aperture Radar (SAR).

Multi-temporal co-polarized and cross-polarized response is compared to volumetric insitu soil moisture for two crops with contrasting biomass and plant height, namely soybean and corn. The considered dataset is comprised by several soybean and corn fields, whose response to microwaves is averaged leading to an overall assessment for each crop. For canopies with large stalks such as corn, observations suggest an important contribution of the double bounce mechanism when soil surface is wet.