International Collaboration Elevates Water Monitoring Quality

Much can be learnt about marine environmental conditions from the colour of the ocean. Earth Observation scientists need to ensure that the instruments measuring the light that is reflected out of the ocean gives consistent results, especially since these are used to verify that the satellite data are accurate.

A team of ocean optics experts, including researchers from Tartu Observatory, evaluated the accuracy of above-water optical sensors, using a community-developed processor, to produce the highest quality data for satellite ocean colour validation and facilitate monitoring the health of our coastal seas and global ocean.

“Routine comparison measurements are essential for validating the Earth observation data. This latest comparison introduces harmonised data processing using the open-source HyperCP community processor, allowing for alignment with widely accepted processing standards and in-depth uncertainty analysis. It is a significant step forward in the highest quality for validating satellite-based Earth observation data products," says Riho Vendt, the Associate Professor at the Tartu Observatory.

In a landmark international study led by Plymouth Marine Laboratory, experts compared above-water radiometers over a ten-day campaign in the Adriatic Sea at the Acqua Alta Oceanographic Tower using an open-source processor, HyperCP.

The results demonstrate that tailoring data processing through HyperCP sharply reduces uncertainties and harmonizes measurements from different radiometers, strengthening confidence in data used to validate satellite ocean colour products. This is critical for monitoring phytoplankton, sediments and dissolved organic matter—key indicators of marine health and climate change impacts.

Read the news about the results of the intercomparison.

Read the full paper.

Go to the website of the intercomparison FICE-22 held in 2022.

From 20 to 22 May 2025, the Tartu Observatory in Tõravere hosted an International Workshop on Calibration and Characterization of Ocean Color Field Radiometers, bringing together leading specialists from around the world. Read more.

The study was part of the Fiducial Reference Measurements for Satellite Ocean Color (FRM4SOC) Phase-2 project, funded by the European Commission Copernicus Programme and implemented by EUMETSAT. The development of HyperCP was initiated by NASA’s HyperInSPACE and the University of Victoria’s PySciDON software processing packages, and is currently being conducted by an international team of expert scientists from institutions such as NASA, NPL, NOAA, EUMETSAT, PML and others. The field experiment, led by PML, was sponsored by the Copernicus Programme in the frame of the second phase of the FRM4SOC study run by EUMETSAT and lead by the University of Tartu.

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