Articles | Volume 7, issue 2
Earth Syst. Sci. Data, 7, 319–348, 2015
Earth Syst. Sci. Data, 7, 319–348, 2015
Review article
20 Nov 2015
Review article | 20 Nov 2015

CoastColour Round Robin data sets: a database to evaluate the performance of algorithms for the retrieval of water quality parameters in coastal waters

B. Nechad1, K. Ruddick1, T. Schroeder2, K. Oubelkheir2, D. Blondeau-Patissier3, N. Cherukuru4, V. Brando4, A. Dekker4, L. Clementson4, A. C. Banks5,20, S. Maritorena6, P. J. Werdell7, C. Sá8, V. Brotas8, I. Caballero de Frutos9, Y.-H. Ahn10, S. Salama11, G. Tilstone12, V. Martinez-Vicente12, D. Foley13,†, M. McKibben14, J. Nahorniak14, T. Peterson15, A. Siliò-Calzada16, R. Röttgers17, Z. Lee18, M. Peters19, and C. Brockmann19 B. Nechad et al.
  • 1Operational Directorate Natural Environment, Royal Belgian Institute for Natural Sciences (RBINS/ODNE), 100 Gulledelle Brussels, 1200, Belgium
  • 2Commonwealth Scientific and Industrial Research Organisation (CSIRO), Land and Water, Environmental Earth Observation Program, P.O. Box 2583, Brisbane, QLD 2001, Australia
  • 3Charles Darwin University, 0815 Darwin, Australia
  • 4Commonwealth Scientific and Industrial Research Organisation (CSIRO), P.O. Box 1666, Canberra, ACT, Australia
  • 5Hellenic Centre for Marine Research (HCMR), Institute of Oceanography, P.O. Box 2214, Heraklion 71003, Crete, Greece
  • 6Earth Research Institute (ERI), University of California, Santa Barbara, CA 93106-3060, USA
  • 7NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
  • 8Marine and Environmental Sciences Centre (MARE), Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016 Lisbon, Portugal
  • 9Institute of Marine Sciences of Andalucia (ICMAN-CSIC) Puerto Real-Cádiz, 11519, Spain
  • 10Korea Ocean Research & Development Institute (KORDI), Ansan, P.O. Box 29, 425–600, South Korea
  • 11Faculty of Geo-information Science and Earth Observation (ITC), Department of Water Resource, University of Twente, Hengelosestraat 99, 7500 AA Enschede, the Netherlands
  • 12Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth PL1 3DH, UK
  • 13National Oceanic and Atmospheric Administration (NOAA), Southwest Fisheries Science Center, 110 Shaffer Road, Santa Cruz, CA 95060, USA
  • 14College of Earth, Ocean and Atmospheric Sciences (CEOAS), Oregon State University, Corvallis, OR, USA
  • 15Center for Coastal Margin Observation and Prediction and Institute of Environmental Health, Oregon Health and Science University, 3181 SW Sam, Jackson Park Road, Portland, Oregon 97239, USA
  • 16Environmental Hydraulics Institute of the University of Cantabria, Cantabria, Spain
  • 17Institute of Coastal Research, Helmholtz-Zentrum Geesthacht, Centre for Materials and Coastal Research, Max-Plank-Str. 1, 21502 Geesthacht, Germany
  • 18School for the Environment, University of Massachusetts Boston, Boston, MA 02125, USA
  • 19Brockmann Consult, Max-Planck-Str. 2, 21502 Geesthacht, Germany
  • 20European Commission – Joint Research Centre (JRC), Institute for Environment and Sustainability, Via Enrico Fermi 2749, Ispra (Va) 21027, Italy
  • deceased

Abstract. The use of in situ measurements is essential in the validation and evaluation of the algorithms that provide coastal water quality data products from ocean colour satellite remote sensing. Over the past decade, various types of ocean colour algorithms have been developed to deal with the optical complexity of coastal waters. Yet there is a lack of a comprehensive intercomparison due to the availability of quality checked in situ databases. The CoastColour Round Robin (CCRR) project, funded by the European Space Agency (ESA), was designed to bring together three reference data sets using these to test algorithms and to assess their accuracy for retrieving water quality parameters. This paper provides a detailed description of these reference data sets, which include the Medium Resolution Imaging Spectrometer (MERIS) level 2 match-ups, in situ reflectance measurements, and synthetic data generated by a radiative transfer model (HydroLight). These data sets, representing mainly coastal waters, are available from doi:10.1594/PANGAEA.841950.

The data sets mainly consist of 6484 marine reflectance (either multispectral or hyperspectral) associated with various geometrical (sensor viewing and solar angles) and sky conditions and water constituents: total suspended matter (TSM) and chlorophyll a (CHL) concentrations, and the absorption of coloured dissolved organic matter (CDOM). Inherent optical properties are also provided in the simulated data sets (5000 simulations) and from 3054 match-up locations. The distributions of reflectance at selected MERIS bands and band ratios, CHL and TSM as a function of reflectance, from the three data sets are compared. Match-up and in situ sites where deviations occur are identified. The distributions of the three reflectance data sets are also compared to the simulated and in situ reflectances used previously by the International Ocean Colour Coordinating Group (IOCCG, 2006) for algorithm testing, showing a clear extension of the CCRR data which covers more turbid waters.

Short summary
The CoastColour Round Robin (CCRR) project (European Space Agency) was designed to set up the first database for remote-sensing algorithm testing and accuracy assessment of water quality parameter retrieval in coastal waters, from satellite imagery. This paper analyses the CCRR database, which includes in situ bio-geochemical and optical measurements in various water types, match-up reflectance products from the MEdium Resolution Imaging Spectrometer (MERIS), and radiative transfer simulations.