The Global Validation of Ers Wind and Wave Products at Ecmwf

Since the beginning of the ERS-1 mission, ECMWF is involved in the global validation and long-term performance monitoring of the wind and wave Fast Delivery products that are retrieved from the Radar Altimeter (RA), the Synthetic Aperture Radar (SAR) and the Active Microwave Instrument (AMI), on-board the ERS spacecrafts. Their geophysical content is compared with corresponding parameters from the ECMWF atmospheric and wave model as well as in-situ observations (when possible). Also, tests on internal data consistency are performed. An ERS-2 on-board failure in January 2001 degraded attitude control. It had a negative, though acceptable, effect on the quality of the RA and SAR related products; however, a detrimental effect on AMI scatterometer winds. The problems in attitude control were gradually resolved, and since August 2003 the quality of all products is nominal.