Radiometric calibration of COMS geostationary ocean color imager

Abstract

Geostationary Ocean Color Imager (GOCI) is under development to provide a monitoring of ocean-color around the Korean Peninsula from geostationary platforms. It is planned to be loaded on Communication, Ocean, and Meteorological Satellite (COMS) of Korea. In this paper main mission of GOCI and corresponding major technical requirements are introduced. Also characteristic of the GOCI radiometric model for calibration is introduced. The GOCI is modeled as a nonlinear system in order to reflect a nonlinear characteristic of detector. Radiometric calibration concept is explained through radiometric parameter estimation method and offset correction method. For the GOCI, the offset signal depends on each spectral channel because dark current offset signal is a function of integration time which is different from channel to channel. The offset parameter estimation method using offset signal measurements for two integration time setting is described. Also error propagation for radiance estimation is examined in this paper. The error propagation for nonlinear GOCI instrument will be slightly larger than a linear instrument. The increase of error propagation induced by the nonlinear parameter depends on the integration time and the input radiance.

A current review of empirical procedures of remote sensing in inland and near-coastal transitional waters

“…The first image from a dedicated ocean-colour geostationary sensor was acquired on 13 July 2010 by the Global Ocean Colour Imager (Korean Aerospace Research Institute) (Kang et al 2006). Future sensors such as the Optical Carbonaceous and anthropogenic Aerosols Pathfinder Instrument (CNES/ESA) (Le Naour et al 2006) and the Geostationary Coastal and Air Pollution Events sensors (NASA) (Al-Saadi et al 2009) will be capable of providing almost continuous data (∼15 min) -the main challenges are related to radiometric resolution and sensitivity due to the distance from the target (Kang et al 2006).…”

Algorithm for retrieval of aerosol optical properties over the ocean from the Geostationary Ocean Color Imager

“…The GOCI has eight spectral channels at 412,443,490,555,660,680,745, and 865 nm. The spatial coverage of GOCI extends to 2500 km × 2500 km, centered at 36°N and 130°E with 500 m resolution (Kang et al, 2006). By taking advantage of geostationary platform, GOCI can provide hourly spectral image which can be used for continuous monitoring of aerosols over cloud-free areas.…”

Estimating ground-level PM<sub>2.5</sub> in eastern China using aerosol optical depth determined from the GOCI satellite instrument

“…Satellite retrievals of aerosol optical depth (AOD), which provide a measure of the amount of light extinction through the atmospheric column due to the presence of aerosols, have long been recognized to relate to ground level PM 2.5 (Wang and Christopher, 2003). Many studies have developed advanced statistical relationships to estimate with high accuracy surface PM 2.5 from satellite AOD (Liu et al, 2009;Kloog et al, 2012;Hu et al, 2013). For example, Ma et al (2014) estimated PM 2.5 concentrations in China from satellite AOD by developing a national-scale geographically weighted regression model, and found strong agreement (r 2 = 0.64) with ground measurements.…”