An Evaluation of the Uncertainty of the GSICS SEVIRI-IASI Intercalibration Products
An Evaluation of the Uncertainty of the GSICS SEVIRI-IASI Intercalibration Products
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DOI：
10.1109/tgrs.2012.2236330
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发表时间：
2013-02
影响因子：
8.2
通讯作者：
T. Hewison
中科院分区：
文献类型：
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作者：
T. Hewison
全球天基相互校准系统产品用于校正Meteosat/SEVIRI（旋转增强可见光和红外成像仪）地球静止成像仪红外通道的校准，其依据是以Metop/IASI（红外大气探测干涉仪）作为参考仪器对同地观测进行比较。根据测量不确定度表示指南，分析交叉校准算法的每一步，以产生全面的误差预算。本文旨在验证质量指标提供的不确定性估计与GSICS校正。所提出的方法提供了一个框架，允许定量的搭配标准和产生的搭配建议进一步的算法改进之间的权衡。结果表明，随机误差占主导地位的系统的，并在校正后的亮度温度的组合标准不确定度（与覆盖因子k = 1）是~ 0.01 K的典型晴空条件下，但迅速增加低辐射-超过一个数量级的210 K场景，对应于冷云顶。
Global Space-based Inter-Calibration System (GSICS) products to correct the calibration of the infrared channels of the Meteosat/SEVIRI (Spinning Enhanced Visible and Infrared Imager) geostationary imagers are based on comparisons of collocated observations with Metop/IASI (Infrared Atmospheric Sounding Interferometer) as a reference instrument. Each step of the cross-calibration algorithm is analyzed to produce a comprehensive error budget, following the Guide to the Expression of Uncertainty in Measurement. This paper aims to validate the quality indicators provided as uncertainty estimates with the GSICS correction. The methodology presented provides a framework to allow quantitative tradeoffs between the collocation criteria and the number of collocations generated to recommend further algorithm improvements. It is shown that random errors dominate systematic ones and that combined standard uncertainties (with coverage factor k = 1) in the corrected brightness temperatures are ~ 0.01 K for typical clear sky conditions but increase rapidly for low radiances - by more than one order of magnitude for 210 K scenes, corresponding to cold cloud tops.