基于RADARSAT-2数据的SAR图像双视向几何校正方法研究

The dual-aspect geometric correction method based on DEM using Radarsat-2 data

针对山区高分辨率雷达卫星Radarsat-2图像的严重几何变形,提出了一种新的双视向雷达图像几何校正方法.实验证明该方法可以有效祛除地形引起的各种几何变形,防止地形引起的后向散射系数的失真,特别是能够有效祛除叠掩和阴影的影响,而这个问题是基于单幅雷达图像的传统几何校正方法无法解决的.为合成孔径雷达(SAR)图像在山区的推广应用提供了重要手段.

Synthetic Aperture Radar（SAR） images reveal serious geometric distortions that are caused by terrain undulations.This paper presents a newly developed method on SAR image geometric correction which is the dual-aspect geometric correction based on digital elevation model（DEM） to overcome the inherent shortages of SAR image such as foreshortening,shadow and layover and correct the distorted or lost backscatter coefficient values in mountainous area.The Radarsat-2 SAR images were used in this study.The results show that this method can effectively eliminate the effect of geometric distortions and compensate the lost or distorted backscatter coefficients,especially is useful for eliminating layover and shadow distortions in SAR images.This method solves the geometric correction problem that cannot be solved with single SAR image.