EOS Validation Program

Institution: NASA Goddard Space Flight Center
Phone: (301) 286-9503
E-mail: stan@ardbeg.gsfc.nasa.gov

Charles R. McClain, GSFC
Stephane Maritorena, Universities Space Research AssociationJohn J. DeLuisi

Final Report, September 2001

The proposed work is relevant for calibration and validation of SeaWiFS, MODIS, ADEOS/OCTS data and other ocean color missions. This measurement program is based on the Atlantic Meridional Transect (AMT) cruises which are conducted twice a year between UK and the Falkland Islands. Five weeks, 50N-50S cruises intersect a broad variety of oceanic systems and atmospheric aerosol regimes. The optical data collection is conducted with several instruments discrete band profiling radiometers (7 channels), two free-fall profiling systems (13 channels) and a hyperspectral radiometer. Such deployment scheme allows intercomparisons between radiometers and assessments of experimental and environmental variability. All instruments are calibrated at least twice a year and their stability during the cruises is verified after every cast using the SeaWiFS Quality Monitor (SQM) built by NIST. CTD, AC-9, fluorometric measurements and HPLC analyses are also performed. The shipboard data are processed in near-real time and can be easily transferred to the SeaWiFS, MODIS and SIMBIOS Projects for comparison with satellite data and archival in the SeaWiFS Bio-optical Archive and Storage System which will also be utilized by SIMBIOS. Beside basic in-water radiance and irradiance measurements, typical "near-real time" derived products are Remote-sensing reflectances, Normalized Water-Leaving Radiances, Diffuse attenuation coefficients as well as CTD and fluorometric measurements.