中文摘要：

详细对比分析了CMOD4,CMOD_IFR2,CMOD5模式函数在不同风速、入射角及相对风向下NRCS的变化情况,其中,在中等风速区间三者的差异较小,而在高风速下,CMOD4,CMOD_IFR2都存在过度响应的情况,另外还探讨了极化比因子的选取问题。本文以丰富图件的形式展现了各CMOD函数在不同条件下的响应情况,可以为正在或即将要使用这些模式函数的学者们提供参考。

英文摘要：

Geophysical model function（GMF） describes the relationship between ocean wind field and normalized radar cross section（NRCS）,which is the foundation for large areas of wind retrieval from scatterometer data.Application in practice for many years,C-band GMF is constantly improving and formed a number of alternative model functions.In this paper,changes of NRCS under different combination of wind speed,incidence angle and relative wind direction are analyzed in details using CMOD4,CMOD_IFR2,CMOD5 model functions.The difference between these model functions is small under medium wind speed and over response of CMOD4,CMOD_IFR2 are found under high wind speed.Additionally,the selection of scale factor for polarimetric ratio is also discussed.The responses of CMOD model functions under different conditions are displayed with abundant graphs which will be of reference value to scholars who are using or about to use these functions.