Overview of the AATSR Validation Programme Marianne Edwards Space Research Centre University of Leicester

AATSR Validation Programme Aims and Objectives Initial Validation - To determine whether the AATSR instrument is returning an acceptable global skin SST (±0.3 K) - To make an initial assessment of the quality of AATSR SST products in a limited number of sites and seasons, including ATSR-2/AATSR cross validation - To assess the accuracy of the AATSR data retrieved over land Ongoing validation - To make a detailed assessment of the quality of AATSR SST products in an increasing number of sites and seasons - To monitor the quality of AATSR data products over the duration of the mission - To validate any new AATSR products

AATSR validation strategy Algorithm verification Validation of the L2 SST product Three levels:- Global comparison of AATSR data against buoys and SST analysis fields Validation using in situ measurements from precision radiometers running autonomously Validation using in situ measurements from precision radiometers on dedicated cruises Validation of visible/near infrared channels from the L1b product Vicarious validation over land and cloud targets Ground based measurements

Envisat Cal/Val Organisation

AATSR ‘Calibration’ Team

AATSR Validation Team

AATSR Validation Team Organisation Coordinated by Validation Scientist at Leicester, on behalf of DEFRA Team meetings 3 Validation team meetings (02/04/01, 28/01/02, 07/11/02) MAVT meetings (15/03/00, 15/11/00, 19/07/01) Reporting Since August 2002 Weekly reporting of the validation team to the VS Weekly reporting by the VS to ESA and DEFRA, and the validation team. Monthly reporting of the validation team and the VS Information dissemination via the AATSR validation website http://www.leos.le.ac.uk/aatsr

Validation activities, May to Validation Workshop

Large number of in situ validation measurements Summary Large number of in situ validation measurements 8 dedicated validation cruises 6 instruments running autonomously Limited number of validation results to date, due to delay in data distribution Now that AATSR data are being received, validation results are being produced