Atmospheric correction of SeaWiFS imagery for turbid waters in Southern China coastal areas

The atmospheric-correction of satellite ocean color data is fundamental for applications of the satellite data. The atmospheric-correction of Sea-viewing Wide Field-of-view Sensor (SeaWiFS) data is successful for open ocean waters, but fails for turbid coastal waters, when using the default algorithm of SeaWiFS Data Analyze System (SeaDAS), resulting in an over-correction of atmospheric effects. Based on the basic principle of atmospheric correction, a practical approach was developed for atmospheric correction of SeaWiFS imagery for turbid coastal waters. We took the assumption of spatial homogeneity of band7-band8 ratio of aerosol radiance and of water-leaving radiance over relatively small spatial scales (100-200 km), the two ratios were calculated from the processed results of SeaDAS standard atmospheric correction algorithm. The correction approach could reduce the errors of water-leaving radiance. In addition the water-leaving radiance in turbid water areas where the default SeaDAS algorithms added a mask for atmospheric correction failure could be retrieved. Then the results were compared with that of other atmospheric-correction method for turbid coastal waters.