Use of Radarsat-2 images to develop a scaling method of soil moisture over an agricultural area

Our objective is to describe and evaluate the spatial variability of the surface soil moisture at small scales using Radarsat-2 images acquired over an agricultural area. To reach this aim, a geostatistical analysis is applied to up scale the soil moisture from ground measurements to the resolution of radar images and also from retrieving soil moisture at different spatial resolution. To conduct this study, four RADARSAT-2 images acquired at different modes during the summer of 2008 over agriculture fields located in Saskatoon (Saskatchewan, Canada) were used. The available data are ground measurements of soil moisture, surface roughness and vegetation characteristics. The comparison between retrieval and ground soil moisture showed average absolute relative errors of about 35% and 55% for fine and ScanSAR mode images respectively. Indeed, a weak amelioration was obtained from the up scaling of the ground soil moisture data to the spatial scale of the different radar image.