Frozen ground deformation monitoring using SAR interferometry

The interferometric SAR technique has demostrated its capability to measure ground deformation in wide range of application. The seasonal freeze/thaw transition will cause the deformation of ground surface, which is the main factor for engineering construction in pemafrost region. China begins construction of Qinghai-Tibet railway in 2002. About 550km of the railway will pass through permafrost areas. Thawing and temperature rising has a great influence on railway stability. In this study, five scences SAR SLC images, including Tandem data, are used to produce multiple imterferograms. Two typical methods for deformation detection are discussed. One is the InSAR measure with the high accurate DEM used to reduce the terrain effect, the other is differential InSAR. The data of deformation in experiment site are compared quantitatively with precise and accurate geodetic data derived from field measurement respectively. The analysis of precision and reliability of two methods showed that the InSAR measure with the high accurate DEM is the suitable technique for deformation monitoring using ERS-1/2 SAR data in Qinghai-Tibet Plateau. Additionally, an InSAR monitoring system of frozen ground deformation is proposed for the Qinghai-Tibet railway building.