本文对应用SAR(Synthetic Aperture Radar)图像反演海面风场方法进行了阐述,并对三种反演模式进行仿真总结。首先介绍SAR图像风场反演的的物理机制,接着介绍风场反演的地球物理模式函数(Geophysical Model Function,GMF),并对CMOD4、CMO...本文对应用SAR(Synthetic Aperture Radar)图像反演海面风场方法进行了阐述,并对三种反演模式进行仿真总结。首先介绍SAR图像风场反演的的物理机制,接着介绍风场反演的地球物理模式函数(Geophysical Model Function,GMF),并对CMOD4、CMOD-IFR2和CMOD5三种模式进行仿真,得到雷达后向散射系数和风速、风向、入射角、极化方式的关系。特别对两个较新的极化比模式进行了介绍和分析。此外对当前应用美国CALIPSO激光雷达卫星资料验证海面风场的方法进行了阐述和探索。展开更多
To retrieve wind field from SAR images, the development for surface wind field retrieval from SAR images based on the improvement of new inversion model is present. Geophysical Model Functions(GMFs) have been widely a...To retrieve wind field from SAR images, the development for surface wind field retrieval from SAR images based on the improvement of new inversion model is present. Geophysical Model Functions(GMFs) have been widely applied for wind field retrieval from SAR images. Among them CMOD4 has a good performance under low and moderate wind conditions. Although CMOD5 is developed recently with a more fundamental basis, it has ambiguity of wind speed and a shape gradient of normalized radar cross section under low wind speed condition. This study proposes a method of wind field retrieval from SAR image by combining CMOD5 and CMOD4 Five VV-polarisation RADARSAT2 SAR images are implemented for validation and the retrieval results by a combination method(CMOD5 and CMOD4) together with CMOD4 GMF are compared with QuikSCAT wind data. The root-mean-square error(RMSE) of wind speed is 0.75 m s-1 with correlation coefficient 0.84 using the combination method and the RMSE of wind speed is 1.01 m s-1 with correlation coefficient 0.72 using CMOD4 GMF alone for those cases. The proposed method can be applied to SAR image for avoiding the internal defect in CMOD5 under low wind speed condition.展开更多
文摘本文对应用SAR(Synthetic Aperture Radar)图像反演海面风场方法进行了阐述,并对三种反演模式进行仿真总结。首先介绍SAR图像风场反演的的物理机制,接着介绍风场反演的地球物理模式函数(Geophysical Model Function,GMF),并对CMOD4、CMOD-IFR2和CMOD5三种模式进行仿真,得到雷达后向散射系数和风速、风向、入射角、极化方式的关系。特别对两个较新的极化比模式进行了介绍和分析。此外对当前应用美国CALIPSO激光雷达卫星资料验证海面风场的方法进行了阐述和探索。
基金supported by the National Natural Science Foundation of China (Nos.41376010 and 40830959)the Start-up Foundation of Zhejiang Ocean University (No.21105011913)
文摘To retrieve wind field from SAR images, the development for surface wind field retrieval from SAR images based on the improvement of new inversion model is present. Geophysical Model Functions(GMFs) have been widely applied for wind field retrieval from SAR images. Among them CMOD4 has a good performance under low and moderate wind conditions. Although CMOD5 is developed recently with a more fundamental basis, it has ambiguity of wind speed and a shape gradient of normalized radar cross section under low wind speed condition. This study proposes a method of wind field retrieval from SAR image by combining CMOD5 and CMOD4 Five VV-polarisation RADARSAT2 SAR images are implemented for validation and the retrieval results by a combination method(CMOD5 and CMOD4) together with CMOD4 GMF are compared with QuikSCAT wind data. The root-mean-square error(RMSE) of wind speed is 0.75 m s-1 with correlation coefficient 0.84 using the combination method and the RMSE of wind speed is 1.01 m s-1 with correlation coefficient 0.72 using CMOD4 GMF alone for those cases. The proposed method can be applied to SAR image for avoiding the internal defect in CMOD5 under low wind speed condition.
