GLaSS Getting Ready to Use Sentinel 2 and 3 for Inland Water Monitoring
Peters, Steef; Hommersom, Annelies; Poser, Kathrin; Laanen, Marnix; de Reus, Nils; Ghezehegn Ghebrehiwot, Semhar

The EU collaborative project Global Lakes Sentinel Services (GlaSS) aims at developing tools, algorithms and applications for the use of Sentinel 2 (S2) and Sentinel 3 (S3) data for monitoring of global lakes and reservoirs.

The ecological state of surface water can be read from several simple measurements and indicators such as the concentration of Chlorophyll-a (Chl-a) as proxy for algal biomass and Secchi disk depth, suspended matter concentration or turbidity, all as measurement or proxy for water transparency. Optical remote sensing techniques can provide these parameters with a high spatial and temporal resolution, thus making it possible to monitor changes in water quality. The high overpass frequency of S3 and the high spatial resolution of S2, combined with their high spatial location accuracy, will provide unprecedented monitoring capabilities for inland waters. However, the large amounts of data that will be produced by S2 and S3 also pose a number of challenges: on the technical side, systems are needed that allow to ingest, archive, process and distribute these data efficiently. But to be turned into information useful for water management, the large quantity of data also requires new methods of data mining and aggregation.

The GLaSS project will develop such a prototype enhanced service infrastructures to ingest and process the expected very large quantities of S2 and S3 data and make them accessible to a larger user community in a harmonised and user-friendly way. Particular focus will be put on adaptation of water quality algorithms to S2 and S3 data, and on the development of user-relevant value adding services. These services will include functionalities for integrated use of Sentinel 2 and 3 data, time series generation, data mining and further analysis.

The quality of the GLaSS system and its products will be ensured by testing it against simulated datasets, and by validating the products through a number of field studies and demonstration cases. The global case studies will demonstrate the applicability of the GlaSS system to very different lake types and management questions.

GLaSS is a FP7 project funded under the Call SPA.2012.1.1-05 Preparing take take-up of GMES Sentinel data. The project is led by Water Insight, project partners are SYKE, EOMAP, IVM-VU, Brockmann Consult, CNR, Tartu Observatory and Brockmann Geomatics.