针对宽观测带SAR图像,在对入射角效应量化研究的基础上,提出了一种入射角效应按类校正方法。利用分水岭分割和区域标记技术实现地物取样,基于结合线性回归估计的余弦朗伯定律,实现对地物后向散射值的按类辐射校正。针对Envisat ASAR C波段HH极化数据的实验结果表明,入射角效应对雷达后向散射有明显的影响,含水量越高的地物类型,入射角效应越明显。利用本文方法进行入射角效应校正的效果优于绝对定标和一阶余弦校正的效果。

Based on a quantitative study of the incident angle effect of a wide-swath synthetic aperture radar (SAR) image, this paper proposes a class-based correction method for such an effect. The method achieves sampling by using watershed segmentation and regional labeling technology as well as a class-based radiation correction of land-cover backscatter values based on the cosine Lamberts law estimated through linear regression. Experimental results of the Envisat Advanced SAR (C-band horizontal-transmitting, horizontal-receiving polarization) data show that an incident angle effect is exerted on radar backscatter; the higher the moisture content of the land-cover type is, the more obvious the incident angle effect is. The correction of incident angle effect with this proposed algorithm is better than order cosine correction.