Validating and exploring EnMAP hyperspectral data in Paraibuna Reservoir, São Paulo, Brazil

This study was conducted at Paraibuna Reservoir in São Paulo State, Brazil. Data obtained by the Environmental Mapping and Analysis Program (EnMAP) satellite were compared with in situ radiometric measurements and further investigated using derivative analysis. The results indicated satisfactory agreement between satellite and in situ spectra, with correlations greater than 0.88. The suspended sediment concentration is possibly the main driver of the spectral behavior in the Paraibuna Reservoir. Additionally, the findings revealed a spatial pattern in the first-order derivative at 600 nm, indicating a higher contribution of suspended sediment from the Paraitinga River. The second-order derivatives highlighted the absorption by phycocyanin at 635 nm and chlorophyll a at 680 nm. Despite the clear water in the study area, EnMAP was able to identify subtle features, demonstrating its potential for studying aquatic systems across diverse optical water types.