Wrapped Interferograms Enhanced By MuLSAR Method: Applications And Comparison To Other Methods

Abstract : SAR interferometry (InSAR) is a powerful technique to monitor surface displacements. However, InSAR suffers from numerous noise sources such as temporal and geometric decorrelation of images. In this study, we apply the MuLSAR method [1] to produce robust denoised wrapped phase time series from the combination of wrapped interferograms, using the redundancy of interferograms. It is particularly efficient in high temporal decorrelation areas. Our method has been applied to ENVISAT time series suffering from diverse temporal decorrelation in three regions: the Himalaya, the Levantine Fault in Lebanon and Western Pakistan. The interferograms are efficiently enhanced for every time series. First, we show that a criterion called colinearity is more efficient than the coherence to quantify wrapped phase quality. The performance of MuLSAR method is demonstrated as it enhances post-processing steps (DEM residual compensation, unwrapping). It is finally compared to another method of wrapped time series enhancement, SqueeSAR [2].