一种多部地基SAR联合观测时的图形配准方法

An Image Registration Method Applied for Joint Measurements of Multiple GB-SAR

地基SAR(Synthetic Aperture Radar,合成孔径雷达)在形变监测领域得到了广泛应用,但仅能获取沿雷达视线方向的一维形变信息。为实现三维形变信息的测量,可以采用多部地基SAR从不同的观测角度对同一区域进行联合观测,但不同雷达的图像特征差别较大,基于常规的多项式拟合的变换方法无法实现配准。因此,本文提出了一种新的适合多部地基SAR联合观测下的几何配准方案。该方案中包含两个关键问题:三维坐标系变换和同名投影点关联,首先基于多个控制点将各部雷达与场景高程信息统一到同一坐标系下,其次基于雷达成像的投影原理实现不同雷达图像中同名投影点的关联。基于两部雷达获取的实测数据,初步验证了该方案的可行性。

GB-SAR (Ground-based synthetic aperture radar) has been widely utilized to monitor surface deformations, which has a major limitation that they can only measure the one-dimensional (1-D) deformation along radar-target line of sight. To measure the 3-D deformations, multiple GB-SAR could be utilized together to observe one monitoring scene from different aspects. However, images acquired by different radar could present obviously different features, which could not be registered with the conventional method of polynomial curve fitting. Therefore, the paper presented a new image registration method applied for joint measurements of multiple GB-SAR. The method mainly included two key aspects: transformation of 3-D coordinate systems and relevance of homonymous projection points. Some reference points were firstly utilized to transform multiple GB-SAR and terrain information into a same coordinate system. Then homonymous projection points were relevant based on the projection principle of GB-SAR imaging. Experimental datasets acquired with two radar systems were utilized to preliminary validate the feasibility of the proposed method.