Integrating Vegetation Phenology in Soil Moisture Change Detection from Asar Wide Swath Images

Multitemporal processing of synthetic aperture radar imagery, e.g. for the extraction of a soil moisture index, requires normalization of acquisitions from different locations in space to a common incidence angle. Incidence angle dependence of backscatter is known to depend on the amount of aboveground vegetation, and can thus be expected to vary seasonally as a result of vegetation phenology. This study tries to assess the impact of vegetation phenology on the angular dependence, and the effect on a soil moisture index derived using a change detection method. It is found that soil moisture accuracy overall decreases when seasonality in the angular dependence of backscatter is ignored.