International SI-traceable Laboratory inter-comparison experiment in Tartu Observatory and Kääriku

Mari Allik | 15.05.2017

Tartu Observatory organized a laboratory inter-comparison  on 8 – 13 May  2017 in the cleanroom laboratories and Lake Kääriku within the FRM4SOC project. The core action of the FRM4SOC project is to ensure that ground-based measurements of ocean colour parameters are traceable to SI standards in support of ensuring high quality and accurate Sentinel-2 MSI and Sentinel-3 OLCI products. 

FRM4SOC 2017 LCE-2

Participants from Germany (Alfred-Wegner-Institut; Helmholtz-Zentrum Geesthacht), Belgium (Royal Belgian Institute of Natural Sciences), Italy (National Research Council of Italy), Portugal (University of Algarve), Canada (University of Victoria; Satlantic), United Kingdom (Plymouth Marine Laboratory; National Physical Laboratory), France (Cimel Electronique S.A.S), European Space Agency and Estonia (Tartu Observatory; University of Tartu) took part in the inter-comparison.

The first three days were spent in Tartu Observatory’s cleanroom laboratories for optical measurements to provide SI-traceable radiometric calibration for participating radiometers and perform laboratory inter-comparison of radiometers in controlled environment. The SI-traceable calibration verifies whether different instruments measuring the same object can provide consistent results within the uncertainty limits.

The outdoor inter-comparison was carried out on the last two days on a diving platform by Lake Kääriku. The Field Ocean Color Radiometers were mounted on racks over the water surface to measure the downwelling irradiance, sky radiance and total water surface radiance.

Additional information: https://frm4soc.org