Closing the Second Year of ESA Satellite Data Simulation for Water Quality Monitoring

The Institute for Environmental Solutions (IES) closes the second year of the European Space Agency (ESA) Sentinel-3 satellite data simulation for water quality monitoring in the Baltic Sea. The performance of Sentinel-3 was simulated by the unique airborne remote sensing system ARSENAL.

According to the HELCOM Monitoring and Assessment Strategy, remote sensing is a complementary monitoring technique to field observations, thereby providing improved information coverage for the Baltic Sea region. The size, complexity and dynamism of marine ecosystems, such as the Baltic Sea, require airborne and field measurements to be collected simultaneously to ensure objective information. Excessive growth of toxic algae caused by eutrophication is the Baltic Sea’s main ecological problem. Thus, the airborne remote sensing missions and field observations were planned for the algae blooming season which tends to occur when the water temperature exceeds 17oC.


The spring/summer season of 2016 was unusual with inappropriate weather conditions for data gathering – high temperature in the early spring resulting in very early algae blooms, as well as prolonged period of cloudy sky (50% cloud cover) during the July and August. Considering that the quality of remote sensing data is dependent on the weather conditions, airborne remote sensing campaigns of Estonian coastal waters were held on the 31st of May and 14th of September. Data were acquired successfully and simultaneously with field measurement campaigns led by the Estonian Marine Institute.



The collected data will be used by IES to continue to develop improved remote sensing algorithm and methods for assessment of water quality parameters in the Baltic Sea. Our Estonian partners, who are established researchers in marine optical sensing and holds a long lasting experience of Baltic Sea research will provide in situ measurements and historical data. Furthermore, IES will involve Baltic Sea data modelling experts from Finland. By fusing Sentinel-3 satellite, airborne remote sensing, in situ, historical and modelled data, IES expects to create comprehensive marine assessment method that is particularly suited for the Baltic Sea.


The use of methods that are based on remote sensing data will provide both wide-scale and real-time data as well as time series, thereby helping to react to emergencies and tracking the impact of managerial decisions. Furthermore, upgraded understanding of the Baltic Sea will open the doors for numerous downstream water quality products, as well as improve the knowledge and skills of Latvian scientists and practitioners in acquiring, processing, analysing and applying earth observation data.

The SentiBalt project (Simulating Performance of ESA Future Satellites for Water Quality Monitoring of the Baltic Sea) No. LV1-27 is funded by the Government of Latvia and ESA Contract under the PECS (Plan for European Cooperation States). The view expressed herein can in no way be taken to reflect the official opinion of ESA.

More about the SentiBalt project