Approaches to Interferogram Generation Based on Coarse DEM
基于粗数字高程模型信息的干涉相位图生成方法

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.