Evaluating sub-pixel offset techniques as an alternative to D-InSAR for monitoring episodic landslide movements in vegetated terrain

摘要: article Spaceborne Synthetic Aperture Radar (SAR) sensors obtain regular and frequent radar images from which ground motion can be precisely detected using a variety of different techniques. The ability to measure slope displacements remotely over large regions have many uses, although the limitations most common- place technique, differential InSAR (D-InSAR), must considered prior interpreting final results. One such limitation is assumption that rates movement given distance cannot exceed thresh- old value, dependent upon pixel spacing SAR wavelength. Characteristic features landslides (i.e. sharp boundary between stable/active range temporally-variable veloc- ities) exhibit high spatial displacement gradients, breaking fundamental for reliable D-InSAR analysis. Areas low coherence are also known hinder exploitation data. This study assesses capability TerraSAR-X Spotlight, Stripmap Envisat monitoring slow-moving Shuping landslide in densely vegetated Three Gorges region, China. In this case study, epi- sodic nature shown measurable limit analysis even highest resolution 11-day TSX Spotlight interferograms. A Sub-Pixel Offset Time-series technique applied cor- ner reflectors (SPOT-CR) only amplitude information as robust method resolving time-varying displacements, with verifiable offset measurements presented