Precipitation Estimation from Remotely Sensed Imagery using an Artificial Neural Network Cloud Classification System
Precipitation Estimation from Remotely Sensed Imagery using an Artificial Neural Network Cloud Classification System
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DOI：
10.1175/jam2173.1
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发表时间：
2004-12-01
期刊：
影响因子：
--
通讯作者：
Gao, XG
中科院分区：
文献类型：
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作者：
Hong, Y;Hsu, KL;Gao, XG
本文介绍了一种基于卫星的降水估计算法-基于人工神经网络的遥感信息降水估计云分类系统。该算法提取本地和区域云的红外（10.7妈妈）地球同步卫星图像估计细尺度（0.04degrees × 0.04degrees每30分钟）降雨分布特征。该算法通过以下步骤将卫星云图处理成像素降雨率：1）将云图分离成不同的云块; 2）提取云的特征，包括冷度、几何形状和纹理; 3）将云块聚类成组织良好的子组; 4）使用雨量计校正的雷达每小时降雨量数据校准分类云组的云顶温度和降雨量（T-b - R）关系。识别并解释了几种具有独特云斑特征和T-b-R曲线的云斑类型。雷达和测量降雨量的测量都被用来评估的PERSIANN CCS降雨量估计在一系列的时间（每小时和每日）和空间（0.04度，0.12度和0.25度）尺度。小时评估显示，在0.04度（0.25度）网格尺度下，相关系数（CC）为0.45（0.59）。冬（夏）季平均日降水CC为0.57（0.63）。
A satellite-based rainfall estimation algorithm, Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks (PERSIANN) Cloud Classification System (CCS), is described. This algorithm extracts local and regional cloud features from infrared (10.7 mum) geostationary satellite imagery in estimating finescale (0.04degrees x 0.04degrees every 30 min) rainfall distribution. This algorithm processes satellite cloud images into pixel rain rates by 1) separating cloud images into distinctive cloud patches; 2) extracting cloud features, including coldness, geometry, and texture; 3) clustering cloud patches into well-organized subgroups; and 4) calibrating cloud-top temperature and rainfall (T-b - R) relationships for the classified cloud groups using gauge-corrected radar hourly rainfall data. Several cloud-patch categories with unique cloud- patch features and T-b-R curves were identified and explained. Radar and gauge rainfall measurements were both used to evaluate the PERSIANN CCS rainfall estimates at a range of temporal (hourly and daily) and spatial (0.04degrees, 0.12degrees, and 0.25degrees) scales. Hourly evaluation shows that the correlation coefficient (CC) is 0.45 (0.59) at a 0.04degrees (0.25degrees) grid scale. The averaged CC of daily rainfall is 0.57 (0.63) for the winter ( summer) season.