Adaptive filtering of interferometric phases at building location

The high-resolution space borne sensor TerraSAR-X shows good ability for extracting height information by use of repeat-pass interferometry. Indeed, the interferometric phase is still noisy due to temporal decorrelation. The new TanDEM-X mission offers for the first time the possibility of performing high resolution single-pass space borne interferometry, providing good coherence, and thus allowing a better mapping of the 3D shape of objects. These data are still affected by noise though and a filtering is prerequisite in order to enhance object recognition. In previous work, we presented several filtering methods in order to reduce the interferometric noise at building location. We particularly showed the benefits of introducing GIS information such as building footprints into the filtering. In this paper, we present a new filtering method, consisting of combining GIS-supported and area filters for better consideration of large building shape. Results of the GIS supported filter and of the new combined filter are presented on TanDEM-X data.