Cloud top phase determination from the fusion of signatures in daytime AVHRR imagery and HIRS data
Cloud top phase determination from the fusion of signatures in daytime AVHRR imagery and HIRS data
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DOI：
10.1080/014311697217062
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发表时间：
1997-10-01
影响因子：
3.4
通讯作者：
Huang, HL
中科院分区：
文献类型：
--
作者：
Hutchison, KD;Etherton, BJ;Huang, HL
本文演示了一种改进的从DMSP SSM/T-2微波测深仪数据中检索水蒸气剖面的方法，该方法使用来自NOAA AVHRR图像的云顶温度作为约束条件。然而，AVHRR图像中云顶温度的自动分析由于光学薄卷云的存在而变得复杂，因为来自下方的上升流辐射的一部分没有衰减到空间。因此，必须首先确定云顶相位，以保证云顶温度的准确规格。本文提出了一种操作环境下云顶阶段规范的新方法。该方法结合了白天AVHRR图像中冰云和水云的双光谱云测试结果，以及基于HIRS数据的CO2切片的云顶压力分析。自动云顶相位分析的准确性与人工分析AVHRR图像进行定量测量。结果表明，AVHRR图像和HIRS数据的云特征融合提高了高分辨率图像中云顶相位的规格，减少了仅基于双光谱技术的分析固有的模糊性。
An improved methodology for the retrieval of water vapour profiles from DMSP SSM/T-2 microwave sounder data has been demonstrated using cloud-top temperatures derived from NOAA AVHRR imagery as a constraint. However, the automated analysis of cloud-top temperature in AVHRR imagery is complicated by the presence of optically-thin cirrus clouds, since a component of the upwelling radiation from below passes unattenuated to space. Therefore, cloud-top phase must first be determined to ensure the accurate specification of cloud-top temperature. In this paper, a new approach is presented for the specification of cloud-top phase in an operational environment. The methodology combines results from bi-spectral cloud tests for ice and water clouds in daytime AVHRR imagery with cloud-top pressure analyses based upon the CO2 slicing of HIRS data. The accuracy of the automated cloud-top phase analyses is measured quantitatively against manual analyses of the AVHRR imagery. It is concluded that the fusion of cloud signatures in AVHRR imagery and HIRS data improves the specification of cloud-top phase in the higher resolution imagery and reduces the ambiguity inherent in analyses based solely upon bi-spectral techniques.