New mode TerraSAR-X interferometry for railway monitoring in the permafrost region of the Tibet Plateau

Permafrost is sensitive to climate change and anthropogenic activities. The interferometric synthetic aperture radar (InSAR) is a new technology allowing us to explore the interaction between the permafrost change and human infrastructures. In this paper, the deformation of the Qinghai-Tibet Railway (QTR) in Beiluhe of the Tibet Plateau (TP) between Jun. and Dec. 2014 is detected using the new mode TerraSAR-X interferometry. In the summer thawing season, the cross-profiles of the railway show the asymmetric “W” pattern settlement, with the local deformation maxima at the transition zones between the embankment slopes and the natural meadow. In contrast, the cross-profiles of the QTR have inverse heaving pattern in the freezing season. Differential settlement occurs along the QTR, probably due to its underlying permafrost conditions. Displacements of the embankments with different proactive cooling measures along the experimental embankment segment are derived, showing their cooling performance.