InSAR Dem Reconstruction Using SRTM Data and ERS-1/2 Interferogram

Interferometric Synthetic Aperture Radar (InSAR) technique of repeat-pass interferometric mode can be used for estimating topography of the earth´s surface. Because of the impact of phase errors, the accuracy of the InSAR derived DEM need to be improved. We proposed a new approach which includes three steps to solve the problem. At first the baseline is estimated and the precise orbit data is utilized to obtain more co-registration accuracy. Secondly phase trends are modeled and removed with a linear regression analysis before converting phase to height with critical points selected in high coherence regions. At last we stimulate the interferometric phase in low coherence regions with the use of SRTM DEM. One pair of ERS-1/2 images and SRTM data covering the mountainous region in central China will be utilized in this work. The effectiveness of our approach is shown in the experiment.