R/V Oceania, Polish Academy of Sciences (IOPAN), in Swedish waters
R/V Oceania, Polish Academy of Sciences (IOPAN), in Swedish waters.
 
AC9 which measures absorption (a) and attenuation (c) at 9 wavelengths. The frame also contains a turbidity meter, a CTD and a backscatter meter
An AC9 is deployed in the water. It measures absorption and attenuation at nine wavelengths. The frame also contains a turbidity meter, a CTD and a backscatter meter.
 

European satellite mission

The Copernicus mission from the European Space Agency (ESA) consist of a system of several new satellites, such as the Sentinel-3. The mission will provide a data service of Earth Observation not seen before with several satellites in orbit at the same time, providing both high temporal and spatial data. ESA’s new Ocean and Land Colour Instrument (OLCI) was launched on the satellite platform Sentinel-3A in early 2016.

- Validation of OLCI will be crucial for describing the reliability and uncertainties of the derived water products, Susanne Kratzer, researcher at the Department of Ecology, Environment and Plant Sciences, explains. In order to validate the satellite data, high quality in situ data measured in the field from ships at the same time as a satellite overpass, are required. 

Measurements at R/V Limanda will be compared to the ones made at R/V Oceania
Measurements made from Askö's R/V Limanda will be compared to the ones made at R/V Oceania.
 

Important to work together and secure data quality

The workshop was conducted by the leading ESA ocean colour validation groups and was coordinated by the remote sensing group at Stockholm University. The inter-calibration exercise was aimed at securing the data quality of remote sensing reflectance over the Baltic Sea. The results will be reported to the European Space Agency and published in a peer-review journal and will contribute to the PhD theses of several PhD students.

Gustaf Dalén lighhouse near Oxelösund
Gustaf Dalén lighhouse near Oxelösund with R/V Oceania in the background.

Participating institutes and organisations:

  • Stockholm University, Sweden
  • Tartu Observatory, Estonia; Instrument inter-calibration in Tartu Observatory
  • IOPAN, Poland (participating with research vessel Oceania)
  • Royal Belgian Institute for Natural Sciences, Belgium, responsible for turbidity inter-calibration
  • NIVA, Oslo, Norway
  • Bio-Optika, UK

Swedish lighthouse equipped with sensors

The Gustaf Dalén lighthouse near Oxelösund has since earlier been equipped with measuring apparatus by the Joint Research Centre in Italy (JRC), and the new measurements from this workshop will be compared to the lighthouse data.

The measurements from Gustaf Dalén can be viewed on the NASA Aeronet-OC web-site: http://aeronet.gsfc.nasa.gov/cgi-bin/type_one_station_seaprism_new?site=Gustav_Dalen_Tower&nachal=0&year=24&month=4&aero_water=0&level=1&if_day=0&if_err=0&year_or_month=0 

More information:
Susanne Kratzer, Department of Ecology, Environment and Plant Sciences, Stockholm University, +46-8-161059, susanne.kratzer@su.se