Intercomparison of spaceborne ocean color measurements between OCI and SeaWiFS

Based on ten ocean color images that were obtained simultaneously by the Oc ean Color Imager (OCI) and the Sea-viewing Wide Field-of-view Sensor (SeaWi FS), an intercomparison study shows that the two data sets are highly corre lated. The data from the two different sensors were processed with SeaWiFS atmospheric correction and bio-optical algorithms to derive the chlorophyll -a concentration (Chl-a). The difference of total radiance received at the sensor of OCI and SeaWiFS is in the range of 3.8% at 510 nm to 21.5% at 865 nm. The difference of Chi-a derived from OCI and SeaWiFS is about 12.4%. C orrelation coefficients between OCI and SeaWiFS of total radiance and Chi-a are higher than 0.91. The validity of the free data from OCI on-board ROCS AT-1, the first scientific experimental satellite of Taiwan, is established .