基于相位梯度的干涉条纹图配准方法

Coregistration of multiple-pass interferograms of a single-baseline InSAR system based on phase gradients

利用单基线InSAR系统对同一地区进行重复观测,是获取多基线干涉数据的一种现实可行的途径.单基线InSAR系统单次航过形成的SAR图像对具有高相干性,利用传统的图像配准方法容易实现配准.然而,多次航过获得的SAR图像存在严重的时间去相干和基线去相干,配准难度很大.但是,多次航过形成的干涉相位图对应于同一数字高程模型(Digital Elevation Model,DEM),因此,多次航过产生的DEM中必然存在相干信息.基于此,提出了一种对干涉相位图的配准方法,此方法充分利用相位梯度信息,解决了单基线InSAR多航过数据处理中的干涉条纹图配准问题.计算机仿真结果验证了本方法能够有效地配准单基线InSAR系统多次航过所获得的干涉条纹图.

It is a practical and feasible way to acquire muhibaseline interferometric data by utilizing repeat passes of a single-baseline InSAR system. Due to the high coherence, the single-pass pair of SAR images generated by a single-baseline InSAR can be eoregistered using conventional methods. However, there exist extreme difficulties in the coregistration operation for multiple-pass SAR images due to the serious temporal and spatial baseline decorrelation, especially in the case of large effective cross-track baseline lengths. Fortunately, the repeat-pass interferograms obtained by a single-baseline InSAR correspond to the identical terrain, i. e., Digital Elevation Model （DEM）. Hence the interferograms contain coherent information, even if the SAR images are decorrelated completely. Based on this point, we propose an innovative strategy to coregister the repeat-pass interferograms instead of the SAR images. Computer simulation results show that the proposed method has the ability to align multiple-pass interferograms of a single-baseline InSAR system accurately.