SENTINEL-1 SENSITIVITY TO SOIL MOISTURE AT HIGH INCIDENCE ANGLE AND ITS IMPACT ON RETRIEVAL

This paper presents an experimental sensitivity analysis of Sentinel-1 (S-1) backscatter to soil moisture (SM) content observed at low (i. e., 33 degrees) and high (i. e., 45 degrees) incidence angles over five agricultural fields of an experimental farm located in the Puglia region (Italy). The analysis focuses on the period from March to June 2017 during which 38 S-1 images along ascending orbits were acquired over the site. Results indicate a slight decrease in the radar sensitivity to SM going from low to high incidence with an impact on SM retrieval error that increases from 5.65 m3/ m3 % to 7.63 m3/ m3 %.