GSICS Inter-Calibration of Infrared Channels of Geostationary Imagers Using Metop/IASI
GSICS Inter-Calibration of Infrared Channels of Geostationary Imagers Using Metop/IASI
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DOI：
10.1109/tgrs.2013.2238544
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发表时间：
2013-03-01
影响因子：
8.2
通讯作者：
Koenig, Marianne
中科院分区：
文献类型：
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作者：
Hewison, Tim J.;Wu, Xiangqian;Koenig, Marianne
全球天基间校准系统（GSICS）的首批产品包括对地球静止卫星上当前气象传感器热红外通道的偏差监测和校准校正。它们使用低地球轨道（LEO） Metop卫星上的高光谱红外大气探测干涉仪（IASI）作为共同的交叉校准参考。本文描述了一种加权线性回归算法，用于比较每对地球静止-近地轨道仪器观测到的并置辐射度。回归系数定义了GSICS校正，其不确定性提供了质量指标，确保了对所选社区参考（IASI）的可追溯性。给出了气象卫星、GOES、MTSAT、风云2号和COMS成像仪的例子。由于热环境、杂散光和光学污染的变化，这些仪器的一些通道显示出随时间变化的偏差。这些结果表明，相互校准如何成为监测和纠正偏差的有力工具，并有助于诊断其根本原因。
The first products of the Global Space-based Inter-Calibration System (GSICS) include bias monitoring and calibration corrections for the thermal infrared (IR) channels of current meteorological sensors on geostationary satellites. These use the hyperspectral Infrared Atmospheric Sounding Interferometer (IASI) on the low Earth orbit (LEO) Metop satellite as a common cross-calibration reference. This paper describes the algorithm, which uses a weighted linear regression, to compare collocated radiances observed from each pair of geostationary-LEO instruments. The regression coefficients define the GSICS Correction, and their uncertainties provide quality indicators, ensuring traceability to the selected community reference, IASI. Examples are given for the Meteosat, GOES, MTSAT, Fengyun-2, and COMS imagers. Some channels of these instruments show biases that vary with time due to variations in the thermal environment, stray light, and optical contamination. These results demonstrate how inter-calibration can be a powerful tool to monitor and correct biases, and help diagnose their root causes.