Developing equal suspended matter retrieval algorithms from two satellite hyperspectral sensors

Abstract. The impacts of climate change in the Mediterranean basin are characterized by the alternation between prolonged droughts and episodes of high-intensity torrential rainfall. These hydrometeorological extremes contribute to severe soil erosion, the extent of which is strongly influenced by the land cover within the catchment area, ultimately affecting the quality of the receiving water body. Taking advantage of the increased availability of hyperspectral imagery in recent years, this study aims to estimate both the concentration and composition of suspended matter in inland waters situated in the eastern Iberian Peninsula. For this purpose, we have relied on 55 in situ samples and their respective reflectance spectra, for 36 sites from the L2D product of the PRISMA mission, and for 19 sites from the L2A product of the EnMAP mission. To obtain algorithms, we first use the ARTMO toolbox to identify the best-performing ones and then determine the same retrieval algorithm for both sensors. For the organic fraction the best algorithm uses the 714 nm band, with a NRMSE of 15% for PRISMA and 10% for EnMAP. For the inorganic fraction, the best-performing algorithm was based on the ratio between the ~705 nm band and the 551 nm band, with a NRMSE of 8% for PRISMA and 5% for EnMAP. Finally, the total suspended matter is the sum of both fractions, with a NRMSE of 9% for PRISMA and 5% for EnMAP.