Development of atmospheric correction for extremely turbid waters of GOCI image using modified MUMM atmospheric correction algorithm

Abstract

The Geostationary Ocean Color Imager (GOCI) area include both oceanic waters(Case-1) and coastal waters(Case-2). Some shallow coastal waters including the Yellow Sea and East China Sea tend to be highly turbid resulting from wind or sediment resuspension due to tidal driven. The standard atmospheric correction algorithm for clear oceanic waters assumes that water-leaving radiances can be negligible at near-infrared (NIR) wavelengths. So all of the satellite measured radiances are assigned to aerosol radiances. However, it is well-known that, near turbid waters, the water-leaving radiances at the NIR wavelengths are significant. Therefore the zero NIR reflectance assumption would cause overestimation of aerosol radiances and thus underestimation of water-leaving radiances if the standard atmospheric correction were adopted to turbid Case-2 waters. The MUMM atmospheric correction algorithm developed for SeaWiFS data processing for turbid waters estimates the NIR water-leaving radiances with assumption of the spatial homogeneity of the ratio of both aerosol reflectance and water-leaving radiance for the NIR wavelengths over the region of interest. Using this algorithm, we can obtain comparatively accurate water-leaving radiances in the moderately turbid waters. However, we found that this algorithm still underestimate the water-leaving radiances at the extremely turbid water.In this studdiment resuspension due to tidal driven. The standard atmospheric correction algorithm for clear oceanic waters assumes that water-leaving radiances can be negligible at near-infrared (NIR) wavelengths. So all of the satellite measured radiances are assigned to aerosol radiances. However, it is well-known that, near turbid waters, the water-leaving radiances at the NIR wavelengths are significant. Therefore the zero NIR reflectance assumption would cause overestimation of aerosol radiances and thus underestimation of water-leaving radiances if the standard atmospheric correction were adopted to turbid Case-2 waters. The MUMM atmospheric correction algorithm developed for SeaWiFS data processing for turbid waters estimates the NIR water-leaving radiances with assumption of the spatial homogeneity of the ratio of both aerosol reflectance and water-leaving radiance for the NIR wavelengths over the region of interest. Using this algorithm, we can obtain comparatively accurate water-leaving radiances in the moderately turbid waters. However, we found that this algorithm still underestimate the water-leaving radiances at the extremely turbid water.In this stud