基于星载SAR数据和模式资料的海面风场变分融合方法研究  

Research on ocean wind variational fusion method based on space-borne SAR and model data

作　　者：陈冠宇 艾未华 程玉鑫 戈书睿 袁凌峰 

机构地区：[1]国防科技大学气象海洋学院,江苏南京211101 [2]中国华阴兵器试验中心,陕西华阴714200 [3]海军海洋水文气象中心,北京100071

出　　处：《海洋气象学报》2017年第4期65-74,共10页Journal of Marine Meteorology

基　　金：国家自然科学基金项目(41475019;41375029)

摘　　要：为实现合成孔径雷达数据与数值预报模式资料融合,提高海面风场精度和业务化运用水平,提出了一种基于星载SAR数据与模式资料的变分融合方法。其研究思路是采用二维连续小波变换提取SAR图像中高精度风条纹风向,结合地球物理模型函数求解海面风场的经向分量和纬向分量,然后采用Kriging插值方法将数值预报模式风速插值到SAR海面风场覆盖区域,得到SAR风速观测算子,由此构建SAR风场与模式风场融合的代价函数,并采用变分方法求解分析风场,最终得到融合后的海面风场结果。仿真分析结果表明,变分融合后的海面风速和风向结果更接近于理想值,尤其在SAR海面风场覆盖区域更为明显。选取ENVISAT/ASAR资料和与其时空匹配的欧洲中期天气预报中心模式风场资料开展实例验证,结果表明融合后的海面风场结果比模式风场更加接近于浮标观测结果。Based on the space-borne SAR（ synthetic aperture radar） data and model data,a variational fusion method is presented to implement the fusion of SAR data and numerical weather prediction model data,and to improve the accuracy of sea surface wind field and operational level. First,two-dimensional continuous wavelet transform is applied to extract wind direction of high precision wind stripe in SAR image,and geophysical model function is used to calculate meridional and zonal components of sea surface wind field. Then the Kriging interpolation method is used to interpolate the wind speed of numerical weather prediction model to the coverage area of SAR sea surface wind field,resulting in that the SAR wind speed observation operator is obtained and the cost function of SAR wind field combined with model wind field is established. The variational method is adopted to solve the analysis wind field.Finally,the sea surface wind field results after fusion are obtained. Simulation results show that through the variational fusion,the sea surface wind speed and wind direction results are closer to the ideal values,especially in the coverage area of SAR wind field. The ENVISAT/ASAR sounding data and the spatial temporally matched model wind data of ECMWF（ European Center for Mediumrange Weather Forecasts）are selected to carry out the case verification,and the results show that the sea surface wind field after fusion is closer to the buoy observed result than the model wind field,so it is confirmed that the variational fusion method is effective.

关 键 词：合成孔径雷达 小波变换 变分融合方法 海面风场 

分 类 号：P407.2[天文地球—大气科学及气象学]