A Novel DEM Imaging Algorithm for Complex Terrain Based on GNSS-InBSAR System

Global Navigation Satellite System (GNSS) based interferometric synthetic aperture radar(InSAR) can be considered as a distributed system. It is required to use digital elevation model (DEM) to obtain high-accuracy interferometric phase. However, using coarse DEM directly will make the edge of target's PSF distorted due to its low two-dimensional resolution. In this paper, a DEM imaging method that combines fitting and smoothing processing is proposed. The fitting processing is based on moving least square and the gaussian kernel with symmetrical transformation is used to realize the smooth effect. The experimental results show that the correlation coefficient of the associated points in imaging pairs has been improved, which proves the effectiveness of the algorithm.