Abstract
COMS (Communication, Ocean, and Meteorological Satellite), the first Korean geostationary meteorological satellite, was launched on 27th June, 2010, and has been fully operating its own missions since the end of in-orbit test period in April 2011. Besides inter-calibration system with Metop/IASI using COMS for infrared radiation based on the GSICS (Global Space-based Inter-Calibration System) Coordinate Center (GCC) distributed Algorithm Theoretical Basis Document (ATBD). In Infrared channels calibrations, the results from Apr. 2011 to Mar. 2012 showed the temperature difference between COMS and IASI is less than 0.10K for IR1(10.8μm), 0.72K for IR2(12.0μm), 0.15K for IR3(6.7μm) and 0.33K for IR4(3.7μm). The IR channel inter-calibration implemented using COMS data has been successfully processed for near real-time operation and posting the analysis of the inter-calibrations on a KMA publicly accessible website. For verifying the visible channel calibration, KMA had established moon-calibration system by developing the method comparing the irradiances between the moon observation data of COMS visible channel and the values from ROLO (Robotic Lunar Observatory) model of USGS as a reference data. For retrieving COMS moon irradiances, we cut the COMS Level 1A data about 1090 X 623 pixels under the consideration of COMS sampling rate 1.75 with the center of the moon. From these reprocessed data, we obtained measured moon irradiance, which were total irradiance of these data, and calculated the ratio of measured irradiance to ROLO model irradiance computed under the same conditions. The results showed that the maximum difference of irradiances between measurement and ROLO model during whole 2011 was less than 3.5%. The trend of the ratio considered as the degradation ratio of COMS visible channel is about 1.5% during the period from Jan.2011 to Dec. 2011.
Inter-calibration of COMS Infrared and Visible Channels
COMS (Communication, Ocean, and Meteorological Satellite), the first Korean geostationary meteorological satellite, was launched on 27th June, 2010, and has been fully operating its own missions since the end of in-orbit test period in April 2011. Besides inter-calibration system with Metop/IASI using COMS for infrared radiation based on the GSICS (Global Space-based Inter-Calibration System) Coordinate Center (GCC) distributed Algorithm Theoretical Basis Document (ATBD). In Infrared channels calibrations, the results from Apr. 2011 to Mar. 2012 showed the temperature difference between COMS and IASI is less than 0.10K for IR1(10.8μm), 0.72K for IR2(12.0μm), 0.15K for IR3(6.7μm) and 0.33K for IR4(3.7μm). The IR channel inter-calibration implemented using COMS data has been successfully processed for near real-time operation and posting the analysis of the inter-calibrations on a KMA publicly accessible website. For verifying the visible channel calibration, KMA had established moon-calibration system by developing the method comparing the irradiances between the moon observation data of COMS visible channel and the values from ROLO (Robotic Lunar Observatory) model of USGS as a reference data. For retrieving COMS moon irradiances, we cut the COMS Level 1A data about 1090 X 623 pixels under the consideration of COMS sampling rate 1.75 with the center of the moon. From these reprocessed data, we obtained measured moon irradiance, which were total irradiance of these data, and calculated the ratio of measured irradiance to ROLO model irradiance computed under the same conditions. The results showed that the maximum difference of irradiances between measurement and ROLO model during whole 2011 was less than 3.5%. The trend of the ratio considered as the degradation ratio of COMS visible channel is about 1.5% during the period from Jan.2011 to Dec. 2011.