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 ...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.展开更多
Dose inter-comparison studies for Co γ-ray and 10 MeV electron beam irradiation were carried out 60 from July to October in 2002. The purpose of the studies was to check the reliability of the alanine-PE film dosime-...Dose inter-comparison studies for Co γ-ray and 10 MeV electron beam irradiation were carried out 60 from July to October in 2002. The purpose of the studies was to check the reliability of the alanine-PE film dosime- ters made by CIAE, which will be used as transfer standard dosimetry system mainly for electron beam irradiation. The expanded uncertainty of CIAE alanine/EPR dosimetry system was 4.1% for doses not higher than 10 kGy and 5.4% for those above 10 kGy (k=2). CIAE alanine-PE film dosimeters were sent to JAERI, RISO (National Labora- tory in Denmark) and INCT respectively, which were irradiated by Co gamma-rays or electron beams in each labo- 60 ratory. The irradiated dosimeters were then sent back to CIAE for electron paramagnetic resonance (EPR) analysis. The agreements were obtained to be ±1.9% for gamma-ray dose measurement and ±4.3% for electron beam dose measurement, which were all within the combined uncertainty of the reference and CIAE alanine/EPR dosimetry system. Furthermore, the overall mean ratio was found to be 0.995 with 1.8% in the coefficient of variation (CV). The preliminary inter-comparison studies indicated that CIAE film alanine/EPR dosimetry system had the potential to be used as a transfer dosimetry system for high dose measurement.展开更多
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)
文摘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.
文摘Dose inter-comparison studies for Co γ-ray and 10 MeV electron beam irradiation were carried out 60 from July to October in 2002. The purpose of the studies was to check the reliability of the alanine-PE film dosime- ters made by CIAE, which will be used as transfer standard dosimetry system mainly for electron beam irradiation. The expanded uncertainty of CIAE alanine/EPR dosimetry system was 4.1% for doses not higher than 10 kGy and 5.4% for those above 10 kGy (k=2). CIAE alanine-PE film dosimeters were sent to JAERI, RISO (National Labora- tory in Denmark) and INCT respectively, which were irradiated by Co gamma-rays or electron beams in each labo- 60 ratory. The irradiated dosimeters were then sent back to CIAE for electron paramagnetic resonance (EPR) analysis. The agreements were obtained to be ±1.9% for gamma-ray dose measurement and ±4.3% for electron beam dose measurement, which were all within the combined uncertainty of the reference and CIAE alanine/EPR dosimetry system. Furthermore, the overall mean ratio was found to be 0.995 with 1.8% in the coefficient of variation (CV). The preliminary inter-comparison studies indicated that CIAE film alanine/EPR dosimetry system had the potential to be used as a transfer dosimetry system for high dose measurement.
