基于卫星SAR图像洋面特征的海表面流速度反演方法研究

项目名称： 基于卫星SAR图像洋面特征的海表面流速度反演方法研究

项目编号： No.41276187

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 天文学、地球科学

项目作者： 谢涛

作者单位： 南京信息工程大学

项目金额： 88万元

中文摘要： 物理海洋学和气候变化研究离不开高频次取样的全球海表面流速度资料。迄今为止，还没有可以直接测量海流速度的卫星传感器。本课题的目的在于发展利用合成孔径雷达（SAR）图像反演海表面流的方法。通过与高频雷达海流数据准同步的散射计和SAR风场数据进行统计，拟合海流速度分别与风速矢量、风应力、风应力的旋度之间的经验关系，建立海表面流对风场的调制模型。基于该模型，研究出强流（海洋锋面）区域SAR图像海表面速度反演方法，并利用实测海流速度验证。利用SAR归一化雷达散射截面(NRCS)图像，采用微正则多分维技术对漩涡、冷暖心环流，溢油等中小尺度特征，进行多分维结构奇的异标量特征提取，探索基于微正则多分维理论和突变洋面特征量的SAR图像反演海表面流速方法，验证并进行方法修正研究。通过本项目研究，推动利用卫星传感器直接测量海流速度技术的发展。

中文关键词： 海流；合成孔径雷达；电磁散射；高频雷达；

英文摘要： Data of high frequency sampling global ocean surface current is essential to studying on physical oceanography and climate changing. Up to now, there is no any remote sensor on satellite which directly retrieval ocean surface current velocities. Method of ocean surface current velocity retrieval from SAR image is developed in this project. The statistics of high frequency (HF) radar current data with quasi-synchronous wind products of scatterometer and SAR are taken statistics to figure out the empirical relation between current velocities and wind speeds, wind stress as well as curl of wind stress. Modulation model of wind fields in response to ocean surface current is established. A retrieval algorithm of current velocity from SAR in strong current (ocean fronts) area is presented and verified with in situ buoy data. Microanonical multifractal technology is used to extract singularity scalar features of mesoscale and small scale feature , such as eddies, warm core ring and oil spill pattern, on SAR NRCS images. Based on the microanonical multifractal theory and surface singularity feature, the method of retrieval current velocity from SAR images is improved, validated and applied into other singularity surface features. Successful results of this project will be useful for the development of measuring current

英文关键词： ocean current；SAR；Electromagnetic scattering；High frequency radar；