Use of Sentinel-1 Multi-Configuration and Multi-Temporal Series for Monitoring Parameters of Winter Wheat

The present study aims to investigate the potential of multi-configuration Sentinel-1 (S-1) synthetic aperture radar (SAR) images for characterizing four wheat parameters: total fresh mass (TFM), dry (TDM), plant heights (He), and water content (WC). Because they are almost independent on weather conditions, we have chosen use only SAR. Samples parameters were collected over seven fields (three irrigated rainfed fields) in Southwestern France. We first analyzed temporal behaviors (He, TDM, TFM WC) between February June 2016. Then, profiles S-1 backscattering coefficients (VV, VH), difference (VH − VV), sum polarizations + VV) their cumulative values two orbits (30 132) during wheat-growing season (from January July 2016). After that, signals statistically compared with all crop considering impact pass orbit, irrigation vegetative periods order identify best configuration estimating parameters. Interesting observed various after separating impacts periods. For orbit 30 (mean incidence angle 33.6°); results show that configurations (with coefficient determination (R2) > 0.7) obtained using VV VH as a function He, TDM WC, second period. 132 43.4°), highest dynamic sensitivities (R2 0.8) Overall, sensitivity data variables depended (orbits polarizations), was often better comparison ones. Significant improvements when index considered He (R² 0.9), 0.9) 0.75) fields, along cycle. estimate WC more limited 0.6) remained period vegetation cycle flowering onwards). Whatever considered, relative errors never exceeded 23%. This has shown importance agricultural practices (irrigation) effectively monitor some data.