A multi-sensor approach for the on-orbit validation of ocean color satellite data products

The validation of satellite ocean color data products is a critical component in establishing their measurement uncertainties, assessing their scientific utility, and identifying conditions for which their reliability is suspect. Such efforts require a considerable amount of high quality in situ data, preferably consistently processed and spanning the satellite mission lifetime. This paper outlines the NASA Ocean Biology Processing Group's (OBPG) method for validating satellite data products using in situ measurements as ground truth. Currently, the OBPG uses the described method for validating several historical and operational ocean color missions. By way of a case study, results for the Sea-Viewing Wide Field-of-View Sensor (SeaWiFS) are shown. These results indicate that for the majority of the global ocean, SeaWiFS data approach the target uncertainties of ± 5% for clear water radiances as defined prior to launch. Our results add confidence in the use of these data for global climate studies, where a consistent, high quality data set covering a multi-year time span is essential.