合成孔径雷达资料反演海面风场的正则化方法研究

Regularization method to retrieve synthetic aperture radar sea surface wind

针对基于散射计地球物理模型函数的合成孔径雷达资料反演海面风场中背景风向存在很大误差的问题,提出了利用正则化方法反演海面风场,并通过L曲线准则对正则化参数进行最优选择,然后对该方法进行仿真试验.试验结果显示,正则化方法反演海面风场的风速和风向的反演精度均优于变分同化方法,分析不同真实风向情况下的反演精度表明,真实风向在45°和135°附近时,风速反演的精度高,真实风向在0°和90°时,风向反演的精度高,这种现象与地球物理模型函数中后向散射截面相对于风向的导数相关.

Due to the fact that the error exists in the priori wind direction for the problem of synthetic aperture radar data sea surface wind field retrieval,the regularization method is used to retrieve the wind field,while the L-curve method is adopted to select the optimal regularization parameter.Simulation experiments show that the retrieval accuracy of the regularization method is better than that of the variational method.Further researches in different true wind direction situations indicate that when the real wind direction is in the vicinity of 45 ° or 135 °,the wind speed retrieval accuracy is higher,when the real wind direction is in the vicinity of 0 ° or 90 °,the wind direction retrieval accuracy is higher,this phenomenon may be related to the derivative of backscatter cross section with respect to the wind direction in geophysical model function.