where \(\varepsilon_{0}\) is the (dimensionless) surface emissivity, σ the Stefan-Boltzmann constant (5.67×10−8Wm-²K-4) and TS the surface temperature (K). Emissivity can be calculated based on empirical equations of the Normalized Difference Vegetation Index (NDVI) and the leaf area index (LAI). The leaf area index (Eq. 6) is calculated by using an empirical equation of the Soil Adjusted Vegetation Index (SAVI) (Allen, Tasumi, Trezza, Bastiaanssen, & Waters, 2002):