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

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。

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.