Unify Different Interferograms to Get the Unique InSAR Time Series

“Long or short baseline interferogram” is a well-known concept in InSAR time series analysis. In different cases, scientists often choose interferograms with different baselines based on some specific criteria, such as the level of coherence, the degree of atmospheric delay, and the length of the spatiotemporal baseline to get the best results. However, a question behind the selection of interferograms still keeps intact, that is, why do different interferograms get different results? The recent case of deriving the postseismic deformation of 2021 Maduo Mw7.4 Earthquake illustrates just how important this question is, in which almost every team achieved different results. We highlight the roles of unwrapping error and fading signal in this case, which can explain why different interferograms can get different results. We also proposed a new method to correct these two error sources. After the correction, we unify the time series results from different interferograms. In addition, we also explored the relationship between fading signal and soil moisture, and successfully mapped the liquefaction related to earthquake using InSAR, which to our knowledge is the first time in the world.