基于ENVISAT ASAR数据的龙目海峡海表流场反演  

Estimation of Sea Surface Current Field in Lombok Strait Based on ENVISAT ASAR Data

作　　者：李晴烁 范陈清 孟俊敏 张杰 柯长青[1] LI Qing-shuo;FAN Chen-qing;MENG Jun-min;ZHANG Jie;KE Chang-qing(School of Geography and Ocean Science,Nanjing University,Nanjing 210023,China;First Institute of Oceanography,MNR,Qingdao 266061,China)

机构地区：[1]南京大学地理与海洋科学学院,江苏南京210023 [2]自然资源部第一海洋研究所,山东青岛266061

出　　处：《海洋科学进展》2022年第3期484-495,共12页Advances in Marine Science

基　　金：国家自然科学基金项目--低空远距离条件下海态与目标一体化雷达探测理论与方法(U2006207)。

摘　　要：基于2003年5月至10月ENVISAT ASAR宽幅模式(Wide Swath Mode,WSM)数据和2003年11月至2004年5月ENVISAT ASAR单视复数模式(Image Mode SLC,IMS)数据,利用多普勒质心偏移法获取了海面运动引起的多普勒质心异常,通过去除风和Bragg波引起的多普勒频移,最终获得龙目海峡海表径向流速。利用AVISO(Archiving,Validation and Interpretation of Satellite Oceanographic Data)流场数据对结果进行了精度验证,并分析了龙目海峡海表流速变化。结果表明:本文反演得到的海表面流速与AVISO流场匹配度较好,其中由WSM数据反演得到的流速与AVISO流场均方根误差为0.28 m/s,IMS数据反演得到的流速与AVISO流速均方根误差为0.37 m/s。在研究区范围内,2003年5月至9月海流流速较大(−2.56~2.51 m/s),10月流速减小(−0.79~0.72 m/s),11月至12月流速逐月增大(−1.64~1.25 m/s),2004年3月流速达到最低值(−0.58 m/s),2004年4月至5月流速逐月增大(−1.46~1.72 m/s);在南半球夏季(12月)和秋季(5月)龙目海峡出现北向逆流,其余皆为南向流。该流场反演方法可有效提取海面流速信息,从而为海面流场变化研究提供有效支撑。In this paper,the ENVISAT ASAR Wide Swath Mode(WSM)data from May to October 2003 and ENVISAT ASAR Image Mode SLC(IMS)data from November 2003 to May 2004 are used to retrieve the radial sea surface velocity of Lombok Strait.The doppler centroid anomaly caused by sea surface motion is obtained by Doppler centroid migration method.Then we remove the doppler frequency shift caused by wind and Bragg waves.The data used to verify the accuracy of the results are AVISO(Archiving Validation and Interpretation of Satellite Oceanographic Data),and the variation of the velocity in Lombok Strait is analyzed.The result shows that the retrieval sea surface velocity has a good matching degree with AVISO flow field,the Root Mean Square Error(RMSE)of sea surface velocity derived from WSM and IMS data shows minimal difference with AVISO,which are 0.28 m/s and 0.37 m/s,respectively.Within the study area,the current velocity is−2.56-2.51 m/s from May to September 2003,which is relatively large during 2003-2004.The current velocity decreases in October(−0.79-0.72 m/s),and increases with the month from November to December(−1.64-1.25 m/s).In March 2004,the current velocity reaches a minimum value of-0.58 m/s,and it increases with the month from April to May 2004(−1.46-1.72 m/s).The northward countercurrent occurs in southern hemisphere summer(December)and autumn(May),and the rest are southward current.

关 键 词：多普勒频移 海表流场 反演算法 时间序列 龙目海峡 合成孔径雷达 

分 类 号：P731.2[天文地球—海洋科学]