基于尺度分离的SAR图像梯度反演海面风向

基于尺度分离的SAR图像梯度反演海面风向 Wind Directions Retrieval Based on Scale Partitioned SAR Images’ Gradients 朱华波 ZHU Hua-bo 1 2 first-author 文必洋 WEN Bi-yang 1 2 黄坚 HUANG Jian 1 2 武汉大学电子信息学院 武汉大学电子信息学院 School of Electronic Information, Wuhan University School of Electronic Information, Wuhan University 武汉大学电子信息学院,湖北,武汉,430072 武汉大学电子信息学院,湖北,武汉,430072 基于数字图像处理知识和大气边界层理论,提出了一种利用合成孔径雷达图像局部梯度反演海面风向的新方法.该方法定义尺度分离后的合成孔径雷达图像梯度方向与风向垂直,而风向就是由所选图像区域出现最多频率的局部梯度所确定.实例研究表明由梯度方法所确定的风向结果与数值预报值十分吻合,其风向均方根误差为3.414°.并且梯度方法在使用谱方法无法获得结果的情况下,仍然能求得正确的风向结果,为提高海面风场反演率奠定了应用基础. This paper presents an new approach which is based on digital image processing and atmosphere boundary theory to the high resolution ocean surface wind directions from synthetic aperture radar（SAR） images. It defines the wind directions normal to the gradients of the image amplitudes, and the direction is determined by the most frequent values of the local gradients. As a case study, the local gradients method is applied in SAR images. The results are very close to actual values, which shows that the local gradients method has high retrieval precision. And in a situation that the spectral method can’t obtain the result, the result can be obtained by local gradients method. It establishes more extensive foundation for retrieving the high-resolution sea wind field. 合成孔径雷达图像 风向 反演 梯度 尺度分离 synthetic aperture radar （SAR） image wind directions retrieval gradient scale partition P732.1 国家863计划资助项目（2001AA631050） 2005-03-01 2021-04-01 3