基于交叉相关法的卫星云图中云团移动的短时预测

A Cloud Movement Short-time Forecast Based on Cross-correlation

在卫星云图应用研究中引入交叉相关法的思想进行云团移动的短时预测。选取连续两个时次的GMS-5卫星云图,将云图区域划分为32×32像素的图像子集,采用交叉相关法计算获取两幅云图的最佳匹配区域,根据前后云图匹配区域的位置和时间间隔,确定出每个图像子集的移动矢量(速度和方向),并对图像子集的移动矢量进行客观分析,其后,基于检验后的云图移动矢量集,利用后向轨迹方法对云图作短时外推预测。试验结果表明,该方法对卫星云图上较为平稳的云团移动的短时预测效果较好,具有直观、定量、快捷的优点。

The paper describes a cloud forecast technique using cross-correlation from two time sequentia GMS-5 images. Cloud movement vectors are retrieved at a 32 × 32 subset of points through application of a cross-correlation analysis. An area in the first of two sequential frames of satellite data is correlated with surrounding areas in the second frame to find the one surrounding area best correlated. The location difference of the areas defines the displacement vector. After the objective analysis of the displacements, using these displacements, forecast are then produced with a backward trajectory technique. The result show that short time forecast of cloud motion with slowly change achieve better result by the quantificational and fast scheme.