Inter-comparison of the Infrared Channels of the Meteorological Imager Onboard COMS and Hyperspectral IASI Data  

作　　者：Dohyeong KIM Myoung-Hwan AHN Minjin CHOI 

机构地区：[1]National Meteorological Satellite Center of the Korea Meteorological Administration [2]Department of Atmospheric Science and Engineering,Ewha Womans University

出　　处：《Advances in Atmospheric Sciences》2015年第7期979-990,共12页大气科学进展（英文版）

基　　金：supported by the project entitled "Development of Meteorological Satellite Operation and Application Technology" of the KMA/NMSC (Korea Meteorological Adminstration/National Meteorological Satellite Center);supported by the Eco Innovation Program of KEITI (Korea Environmental Industry & Technology Institute) (Grant No. 2013000160002)

摘　　要：The successful launch and commissioning of the first geostationary meteorological satellite of Korea has the potential to enhance earth observation capability over the Asia Pacific region. Although the specifications of the payload, the mete- orological imager （MI）, have been verified during both ground and in-orbit tests, there is the possibility of variation and/or degradation of data quality due to many different reasons, such as the accumulation of contaminants, the aging of instrument components, and unexpected external disturbance. Thus, for better utilization of MI data, it is imperative to continuously monitor and maintain the data quality. As a part of such activity, this study presents an inter-calibration, based on the Global Space-based Inter-Calibration System （GSICS）, between the MI data and the high quality hyperspectral data from the In- frared Atmospheric Sounding Interferometer （IASI） of the Metop-A satellite. Both sets of data, acquired for three years from April 2011 to March 2014, are processed to prepare the matchup dataset, which is spatially collocated, temporally concurrent, angularly coincident, and spectrally comparable. The results show that the MI data are stable within the specifications and show no significant degradation during the study period. However, the water vapor channel shows a rather large bias value of -0.77 K, with a root-mean-square difference （RMSD） of around 1.1 K, which is thought to be due to the shift in the spectral response function. The shortwave channel shows a maximum RMSD of around 1.39 K, mainly due to the coarse digitization at the lower temperature. The inter-comparison results are re-checked through a sensitivity analysis with different sets of threshold values used for the matchup dataset. Based on this, we confirm that the overall quality of the MI data meets the user requirements and maintains the expected performance, although the water vapor channel requires further investigation.The successful launch and commissioning of the first geostationary meteorological satellite of Korea has the potential to enhance earth observation capability over the Asia Pacific region. Although the specifications of the payload, the mete- orological imager （MI）, have been verified during both ground and in-orbit tests, there is the possibility of variation and/or degradation of data quality due to many different reasons, such as the accumulation of contaminants, the aging of instrument components, and unexpected external disturbance. Thus, for better utilization of MI data, it is imperative to continuously monitor and maintain the data quality. As a part of such activity, this study presents an inter-calibration, based on the Global Space-based Inter-Calibration System （GSICS）, between the MI data and the high quality hyperspectral data from the In- frared Atmospheric Sounding Interferometer （IASI） of the Metop-A satellite. Both sets of data, acquired for three years from April 2011 to March 2014, are processed to prepare the matchup dataset, which is spatially collocated, temporally concurrent, angularly coincident, and spectrally comparable. The results show that the MI data are stable within the specifications and show no significant degradation during the study period. However, the water vapor channel shows a rather large bias value of -0.77 K, with a root-mean-square difference （RMSD） of around 1.1 K, which is thought to be due to the shift in the spectral response function. The shortwave channel shows a maximum RMSD of around 1.39 K, mainly due to the coarse digitization at the lower temperature. The inter-comparison results are re-checked through a sensitivity analysis with different sets of threshold values used for the matchup dataset. Based on this, we confirm that the overall quality of the MI data meets the user requirements and maintains the expected performance, although the water vapor channel requires further investigation.

关 键 词：meteorological imager inter-comparison instrument long-term stability water vapor channel 

分 类 号：P412.27[天文地球—大气科学及气象学]