基于TRMM VIRS可见光和红外五通道的白天云检测方案

大气与环境光学学报 ›› 2010, Vol. 5 ›› Issue (2): 128-140.

基于TRMM VIRS可见光和红外五通道的白天云检测方案

刘显通1，刘奇1，傅云飞1，程静2

（1 中国科学技术大学地球和空间科学学院，安徽合肥 230026；
2 上海市气象信息传媒中心，上海 200030）

收稿日期:2009-09-07 修回日期:2009-09-28 发布日期:2010-03-22
通讯作者: 傅云飞，教授，中国科学技术大学地球与空间科学学院。 E-mail:fyf@ustc.edu.cn
作者简介:刘显通（1985-），男，江西人，博士研究生。研究方向为利用卫星遥感资料研究云和降水。
基金资助:
国家自然科学基金重点项目（40730950）、国家自然科学基金青年项目（40805007）资助

A Daytime Cloud Detection Scheme Relying on Five-Channel Measurements from TRMM VIRS

LIU Xian-Tong1, LIU Qi1, FU Yun-Fei1, CHENG Jing2

(1 School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026, China;
2 Media Center of Meteorological Information of Shanghai, Shanghai 200030, China)

Received:2009-09-07 Revised:2009-09-28 Online:2010-03-22

摘要/Abstract

摘要：

热带测雨卫星（Tropical Rainfall Measuring Mission, TRMM）积累的从可见光到微波的多光谱云和降水辐射信息，为全球尺度云和降水参数反演研究提供了宝贵资料。云/晴空识别作为反演流程中的关键一环，对反演结果准确度起到决定性作用。利用可见光/红外扫描仪（visible and infrared scanner, VIRS）提供的五通道辐射通量观测，本文提出一种可依靠TRMM平台观测资料独立实现的白天云检测方案。此方案由地形识别、二维表云检测和决策树云检测三个基本步骤构成，检测结果分为无云覆盖、部分云覆盖和完全云覆盖三种。与MODIS云产品的对比结果表明，非冰雪下垫面云检测精度较高，云量均值差异低于5%。特别对于冰雪下垫面，本方案结合使用1.6 μm反射率以及3.7 μm和10.8 μm亮温信息，利用阈值法对冰雪覆盖的晴空像素和真实云像素实现了较好的分离。利用该云检测方案，仅借助TRMM平台可见光和红外多通道资料即获得可信的云/晴空识别，这将为基于TRMM卫星多仪器融合资料的云和降水参数反演等相关研究带来方便。

关键词: 云检测, 热带测雨卫星, 可见光红外扫描仪

Abstract:

The Tropical Rainfall Measuring Mission (TRMM) satellite has collected a plenty of radiances from global clouds and precipitation, providing invaluable datasets for parameter retrieval of clouds and precipitation, in which cloud detection undoubtedly plays a key role. A cloud detection scheme, available during daytime, was proposed relying on five-channel measurements from TRMM visible and infrared scanner (VIRS). Three kinds of pixels including clear-sky, mixed-cloudy and cloudy ones are separated by such a scheme, which contains three major steps, i.e., terrain recognition, two-dimensional table search and decision tree determination. A comparison was conducted specially with MODIS standard cloud products to verify the cloud detection. It was demonstrated that the accuracy of cloud detection is satisfied on the whole, especially for grounds that are not covered by snow and ice, with mean cloud fraction bias less than 5%. When applied to cases companied by snow and ice in winter and or over plateau area, the 1.6 μm channel reflectivity information, combined with 3.7 μm and 10.8 μm channel BT, were used to identify snow and ice covered sky in this cloud detection scheme, which made snow-covered sky pixels and cloud pixels well separated. Therefore, the proposed cloud detection scheme can be used to TRMM VIRS with considerable reliance, which leads to great convenience for further application of associated TRMM multiple-sensor measurements.

Key words: cloud detection, tropical rainfall measuring mission, visible and infrared scanner

中图分类号:

刘显通刘奇傅云飞程静. 基于TRMM VIRS可见光和红外五通道的白天云检测方案[J]. 大气与环境光学学报, 2010, 5(2): 128-140.

LIU Xian-Tong, LIU Qi, FU Yun-Fei, CHENG Jing. A Daytime Cloud Detection Scheme Relying on Five-Channel Measurements from TRMM VIRS[J]. Journal of Atmospheric and Environmental Optics, 2010, 5(2): 128-140.

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