基于粗数字高程模型信息的干涉相位图生成方法

该文提出了一种基于粗数字高程模型(DEM)信息的干涉相位图生成方法，其思路为充分利用已有的DEM信息来完成SAR图像配准-干涉相位滤波处理。此方法首先根据粗DEM信息和系统参数计算得到SAR图像中每一像素的2维配准偏移量，从而完成SAR图像的配准。在干涉相位滤波中，由粗DEM信息仿真生成已知地形的干涉条纹图用以补偿InSAR系统录取得到的干涉相位，再对残余相位进行滤波处理，提高干涉相位滤波的性能。另外，对于高分辨率SAR图像，粗DEM高程误差和系统参数误差会引入较大的图像配准误差，该文再利用联合像素子空间投影方法进一步完成SAR图像的精确配准和相位滤波。仿真结果验证了该文方法的有效性。

Approaches to Interferogram Generation Based on Coarse DEM

This paper investigates practical processing approaches for interferogram generation based on coarse DEM (Digital Elevation Model). The key point of the proposed method is to make full use of available coarse DEM to complete the operations of SAR image coregistration and interferometric phase filtering. The method firstly computes the two dimensional shift amounts of each pixel in SAR image according to the coarse DEM and system parameters, thereby achieving image coregistration. For phase filtering, interferograms corresponding to the coarse DEM are used to compensate the terrain changes so that independent and identically distributed (i.i.d.) samples are obtained to increase the performance of phase filtering. And then the compensated phase is added to the filtered results. In the case of high-resolution SAR images, the coregistration error caused by the system parameters and coarse DEM maybe not meet the requirement of InSAR processing. Consequently, the joint pixel subspace projection is adopted to increase the accuracy of image coregistration and achieve well performance of phase filtering. Finally, computer simulation verifies the validity of the proposed algorithm.