Creep identification by the baseline optimized TS-InSAR technique considering the monthly variation in coherence

Abstract

Time series interferometric synthetic aperture radar (TS-InSAR) technique can be applied to identify the creep body. However, it has strict requirements regarding the quality of the interferograms and the interferometric baseline networks. In regions with intermittent coherence, the use of conventional methods to select interferometric pairs can easily lead to interferometric baseline disconnections, redundancy, or missing key pairs. This results in reduced accuracy and may even misidentify creep characteristics. To solve this problem, the segmented average coherence threshold method (SACTM) is proposed. SACTM is an interferometric baseline optimization method that considers monthly coherence variability. In this paper, the SACTM baseline optimization TS-InSAR technique was used to identify creep bodies in Wudongde Reservoir area located along the Jinsha River in China. Compared with the conventional methods, the SACTM method yields a more robust interferometric baseline network and a smaller standard deviation for deformation rate, which demonstrates the superiority of this method.