FY-4B与FY-4A云顶性质产品精度的一致性评估

Consistency of the Accuracy of FY-4B and FY-4A Cloud Top Products

关键词:  FY4  云顶温度  云顶高度  云顶压强  精度检验

Key words:  FY-4  cloud-top temperature  cloud-top height  cloud-top pressure  accuracy validation

摘要:

风云四号（FY4）气象卫星是我国第二代静止气象卫星，FY4B 云顶温度、云顶高度和云顶压强的反演算法与 FY4A相同，为了方便用户更好地应用 FY4B云顶产品，本文利用美国 EOS/MODIS极轨气象卫星和日本第二代静止气象卫星 Himawari-8云产品检验 FY4A 和 FY4B反演的云顶产品精度的一致性，结果表明，FY4B云顶产品与 FY4A具有很好的一致性，其中 B星多层云的较大误差主要是由于云分类将卷云错判成了多层云所致。从全样本的检验结果可以看出 FY4B云顶参数产品的精度与 FY4A 精度大体相当，两者的差异主要来自于通道光谱特征的改变、定标精度及所用的辐射传输模式的不同。

Abstract:

The FengYun-4 (FY-4) meteorological satellite is the second generation of China’s geostationary meteorological satellite. FY-4B satellite utilizes identical algorithms as its predecessor, FY-4A, for retrieving cloud top temperature, height, and pressure. To facilitate the application of FY-4B cloud top products, this paper evaluated the consistency of the accuracy of the cloud top retrievals from FY-4A and FY-4B, and compared them with those from the EOS/MODIS polar-orbiting meteorological satellite of the United States and Himawari-8, Japan’s second-generation geostationary meteorological satellite. The results show that the cloud top retrievals from FY-4B exhibited good consistency with those from FY-4A. The larger error in FY-4B’s classification of multi-layer clouds mainly arose from the misclassification of cirrus clouds into multi-layer clouds. The validation results of the whole sample show that the accuracy of FY-4B cloud top retrievals is consistent with that of FY-4A. The discrepancies between them are primarily attributed to the variations in channel spectral characteristics, calibration accuracy, and the difference in the radiative transfer model used.