Analysis of watet-leaving reflectance models for turbid waters in the coverage of Geostationary Ocean Color Imager (GOCI)

Abstract

The standard atmospheric correction algorithm for clear oceanic waters assumes that water-leaving radiances can be negligible at near-infrared (NIR) wavelengths. Therefore all of satellite measured radiances are assigned to aerosol radiances. However it is well known that the assumption is not satisfied in turbid waters due to backscattering signal from resuspended sediment particles.To separate the water-leaving reflectance at NIR from the aerosol reflectance, accurate estimation of water-leaving reflectance is crucial. Various studies have proposed empirical relationship between two water-leaving reflectance for accurate estimation during atmospheric correction. Wang et al (2012) proposed regional NIR water-leaving radiance model for Geostationary Ocean Color Imagery (GOCI) data atmospheric correction. This model includes the Yellow Sea, East China Sea and Bohai Sea. Ahn et al (2012) found empirical NIR water-leaving reflectance polynomial which was derived from GOCI. This polynomial includes Yellow Sea, East China Sea and Bohai Sea. In this study, we propose subdivided NIR water-leaving reflectance models for each of Mokpo peninsula, Gyunggi bay, East China Sea and Bohai Sea using GOCI satellite data obtained from 2011 to 2013. By using radiative transfer simulation (Hydrolight version 5), we analyzed models which was shown differently depending on optical properties of four ocean site.s. However it is well known that the assumption is not satisfied in turbid waters due to backscattering signal from resuspended sediment particles.To separate the water-leaving reflectance at NIR from the aerosol reflectance, accurate estimation of water-leaving reflectance is crucial. Various studies have proposed empirical relationship between two water-leaving reflectance for accurate estimation during atmospheric correction. Wang et al (2012) proposed regional NIR water-leaving radiance model for Geostationary Ocean Color Imagery (GOCI) data atmospheric correction. This model includes the Yellow Sea, East China Sea and Bohai Sea. Ahn et al (2012) found empirical NIR water-leaving reflectance polynomial which was derived from GOCI. This polynomial includes Yellow Sea, East China Sea and Bohai Sea. In this study, we propose subdivided NIR water-leaving reflectance models for each of Mokpo peninsula, Gyunggi bay, East China Sea and Bohai Sea using GOCI satellite data obtained from 2011 to 2013. By using radiative transfer simulation (Hydrolight version 5), we analyzed models which was shown differently depending on optical properties of four ocean site.