Variation in coherence for fixed ground objects derived from bi-static TerraSAR-X/TanDEM-X data

Inhalt:
The coherence of the interferometric pair of two Synthetic Aperture Radar images between pre- and post-disaster has been widely used for disaster damage mapping. Bi-static acquisition by TerraSAR-X/TanDEM-X has been performed since 2011, and is expected to be used for single-pass interferometry owing to its non-atmospheric disturbance. The purpose of this study is to acquire knowledge regarding coherence in single-pass interferometry at fixed ground objects of roads, parking lots, and parks. The generated coherence was quantitatively high even in the natural objects comparing with that of repeat-pass acquisition. The range of coherence values for a park was larger than those of a road or a parking lot. Furthermore, the coherence at each validation point varied by approximately 10% by acquisition dates, despite the single-pass interferometry.