【摘要】 本文选取142幅RADARSAT-2全极化合成孔径雷达(SAR)影像,在没有入射角输入的情况下,首先利用C-2PO模型进行海面风速反演。随后,将同一时空下的ASCAT散射计风向作为初始风向,提取相应雷达入射角,利用地球物理模式函数(GMF)CMOD5.N对142幅SAR影像进行风速计算。反演结果与美国国家资料浮标中心海洋浮标风速数据对比,结果显示:CMOD5.N GMF和C-2PO模型均可反演出较高精确度的海面风速,其均方根误差分别为1.68 m/s和1.74 m/s。此外,研究发现,在低风速段,CMOD5.N GMF的风速反演精度要明显优于C-2PO模型。针对这一现象,本文以SAR系统成像机理为基础,以低风速SAR图像为具体案例,给出了3种造成这一现象的原因。更多还原

【Abstract】 In this paper,we first retrieve ocean surface wind speed from C-2 PO model without incidence angle input using selected 142 quad-polarized synthetic aperture radar( SAR) images. Subsequently,wind speed computed from geophysical function model( GMF) CMOD5. N with incidence angle measured from the advanced scatterometer( ASCAT) using the same SAR images. Compared with national data buoy center( NDBC) buoy-measured wind speed,the results show that the ocean surface wind speed retrieve from CMOD5. N GMF and C-2 PO model both have a high accuracy,and with the root-mean-square( RMS) error are1. 68 m/s and 1. 74 m/s,respectively. In addition,the wind speeds retrieval RMS error of CMOD5. N GMF is perform better than C-2 PO model at low wind speed section( 0-10 m/s). After that,taken one SAR image with low wind speed,three reasons of this phenomenon are presented in this paper based on SAR system imaging mechanism.更多还原