Soil Moisture Mapping Using Sentinel-1A Synthetic Aperture Radar Data

Abstract

The aim of this study is to estimate and map soil moisture distribution using C-band Synthetic Aperture Radar (SAR) data. Sentinel-1A is a new generation C-band SAR satellite, and in this study Sentinel-1A data acquired on 24 April 2016 were used to retrieve soil moisture map. An agricultural region in Bergama, a district of İzmir city, was chosen as the study area. In-situ soil moisture measurements were carried out in 20 test fields simultaneously with SAR data acquisition. The effects of soil moisture and local incidence angle on backscattering coefficient were analyzed, and then a multiple regression analysis was performed to generate an empirical model. The proposed model was evaluated using statistical metrics namely coefficient of determination (R2) and Root Mean Square Error (RMSE), and the results were 0.84 and 2.46 %, respectively. The obtained results showed that Sentinel-1A SAR data presented satisfying outcomes to estimate and map soil moisture content.