Quantification of Temporal Decorrelation in X-, C-, and L-Band Interferometry for the Permafrost Region of the Qinghai–Tibet Plateau

Over the permafrost region of the Qinghai-Tibet Plateau, serious decorrelation has restricted the inteferometric synthetic aperture radar (InSAR) techniques in monitoring ground deformation and thaw-melt hazards. Improved understanding, quantification and prediction of the coherence evolution with time are key prerequirements for choosing the optimal observation time and band in such interferometric applications. In this letter, considering the main processes of degradation and the freeze-thaw cycle, a temporal decorrelation model including both the long-term and seasonal coherence factors is proposed. Multitemporal L-band PALSAR, C-band ASAR, and X-band TerraSAR were collected to validate the model's applicability. Coherence matrices of several typical features were estimated for the parameter inversion. Root-mean-square errors ranging from 0.048 to 0.152 showed good fitting results between the model predictions and the estimated interferometric coherences. The temporal decorrelation characteristics of the permafrost region at the three frequencies were successfully revealed. This letter could also facilitate applications of InSAR techniques in similar areas in other parts of the world.