Nonlocal InSAR filtering for high resolution DEM generation from TanDEM-X interferograms

We investigate the feasibility of generating highly accurate digital elevation models (DEM) from TanDEM-X interferograms by using nonlocal filters for phase denoising. Some of the shortcomings of existing nonlocal filters that render them not applicable to our goal are briefly described and a new filter is proposed that alleviates these problems. The most significant new properties are addressing the slope dependent denoising performance of existing nonlocal InSAR filters and several measures to bolster denoising near edgelike features. We evaluate the proposed filter using synthetic interferograms and by visual inspection of a DEM generated from a TanDEM-X interferogram.