Atmospheric Transmission and Surface Reflection Determination for the Geostationary Environment Monitoring Spectrometer (GEMS)

Abstract:

Evaluation of both atmospheric transmission and surface reflection is an essential issue in the assessment of air quality from satellite observations at different scales. However, large uncertainties may exist in the satellite remote sensing caused by incomplete information on the optical, microphysical properties of them. Recently, new geostationary satellites, the Geostationary Environment Monitoring Spectrometer (GEMS) onboard the Geostationary Korea Multi-Purpose Satellite 2 (GEO-KOMPSAT-2), have been successfully launched and multi-spectral sensors have been operated to observe continuously over East Asia. In this study, atmospheric transmission and surface reflection over East Asia are estimated by the newly implemented algorithm based on the multi-directional and multi-spectral geostationary satellite observation data. In detail, the timely observed trace gases data were used to derive atmospheric transmission, that was applied to retrieve surface reflection by combining the atmospheric correction and minimum reflection composite technique. Then these surface reflection data can be used near-real-time derivation of other level-2 air quality products. A large number of data processed in this method have been compared with the other operational satellite and ground based products. There were good agreements between the products retrieved with the current operational MODIS products, and sun photometer products. Moreover, the proposed method for atmospheric transmission and surface reflection retrieval from the geostationary satellite is promising for monitoring environmental changes with its enhanced spatial and temporal resolution.

acknowledgement

This research was supported by Korea Ministry of Environment (MOE) as "Public Technology Program based on Environmental Policy (2017000160003)“