Qualification of water quality retrieval from OLI-MSI-OLCI for European inland waters

The aim of the study is to test suitability of latest generation of satellite sensors (i.e. Landsat-8 OLI, Sentinel-2 MSI, Sentinel-3 OLCI) with improved resolutions for mapping water quality in different inland waters. Although not specifically designed for water quality applications, these sensors seem to be a valuable tool for inland water monitoring, especially taking into account that the data will be available routinely for many years, and the imagery will be frequent and free of charge. The sites investigated in this study encompass water bodies with rather different characteristics distributed across Europe: the eutrophic large shallow Curonian Lagoon with recurrent blooms of cyanobacteria, deep clear lakes in the subalpine region (Maggiore, Como, Iseo and Garda) and two turbid and eutrophic shallow lakes (Balaton and Mantua). For these sites we had the opportunity to perform a total of 25 field campaigns in the last three years. A significant number of match-ups with satellite acquisitions were therefore available for evaluating satellite products in terms of water reflectance and of concentrations of water components such as chlorophyll-a, total suspended matter and colored dissolved organic matter. Depending on sensors' characteristics and on optical properties of the investigated waters, a number of algorithms suggested by EU/Copernicus projects (e.g. GLaSS and INFORM) were applied to satellite data to derive water reflectance and consequently the concentrations of water components. This study will show the results of the match-up analysis.