Ocean color instrument intercomparisons and cross-calibrations by the SIMBIOS project

The Sensor Intercomparison and Merger for Biological and Interdisciplinary Oceanic Studies (SIMBIOS) Project has a worldwide, ongoing ocean color data collection program, plus an operational data processing and analysis capability, SIMBIOS data collection takes place via the SIMBIOS Science Team and the Aerosol Robotic Network (AERONET). In addition, SIMBIOS has a calibration and product validation component. The primary purpose of these calibration and product validation activities are to (1) reduce measurement error by identifying and characterizing true error sources such as real changes in the satellite sensor or problems in the atmospheric correction algorithm, in order to differentiate these errors from natural variability in the marine light field; and (2) evaluate the various bio-optical algorithms being used by different ocean color missions. For each sensor, the SIMBIOS Project reviews the sensor design and processing algorithms being used by the particular ocean color project, compares the algorithms with alternative methods when possible, and provides the results to the appropriate project office, e.g., Centre National D'Etudes Spatialle (CNES) and National Space Development Agency of Japan (NASDA) for Polarization and Directionality of the Earth's Reflectance (POLDER) and Ocean Color and Temperature Sensor (OCTS), respectively. In the near future the Project is looking forward to collaborate with Global Imager (GLI), Ocean Color Imager (OCI) and international entities such as the International Ocean-Colour Coordinating Group (IOCCG) and Space Application Institute (Joint Research Center).