Polarimetric interferometic coherence optimization based DEM extraction method for ALOS PALSAR data

The primary aim of this study was to extract DEM using Polarimetric SAR Interferometry (Pol-InSAR) ALOS/PALSAR data. We make use of three Pol-InSAR coherence optimization methods, including Singular Value Decomposition, Numerical Radius and Phase Diversity ways, to extract DEM with processing of filtering, unwrapped phase, base-line estimation and so on. At the end, compare optimized results with the single polarimetric interferometry such as HH, HV and VV. It has been observed that optimization ways can reduce the interferometric noise, reduce the phase unwrapping residuals, and improve the precision of the DEM extraction. Meanwhile, Numerical Radius approach has a better result than Singular Value Decomposition and Phase Diversity ways; Interferogram with integrated Contoured Median and Goldstein two-step filter method can further improve and optimize the quality of the interferogram, reduce residual mostly, improve the precision of the DEM, but if two-step filter window setting big will affect the area of non-water-covers while improve the water-covers area.