Fusion of prior information and multi-scales local frequencies to facilitate D-InSAR phase unwrapping

Abstract

In this paper, a dedicated phase unwrapping approach, taking a priori information into account and combining multi-scales local frequencies of the interferometric phase, is developed in order to get around of the discontinuity and aliasing problems. In this approach, the interferogram is characterized by local frequency of the phase. The multi-scales local frequencies of the interferometric phase are estimated and fused to the local frequency at the optimal scale. This optimal scale, the lowest resolution scale allowing phase unwrapping without aliasing problem, is determined from the a priori displacement information. The application is performed on the displacement measurement of the 2005 Kashmir earthquake. The a priori displacement information is issued from a deformation model. The advantages of this approach are highlighted by the obtained results.

Fusion of Remotely Sensed Displacement Measurements: Current status and challenges

“…Besides the displacement measurements, the deformation model also provides useful displacement information, especially when displacement measurements are not available over some areas or during some periods. Fusion between the measurements and the predictions of the model in different manners has also been reported in previous works [78,7,111,34].…”

“…In this way, the phase unwrapping error is reduced significantly. In [111,34], authors estimated the displacement field with the help of a mechanical deformation model and used multi-scale local frequencies of the phase (phase gradient) for phase unwrapping. Thanks to this method, the DInSAR has been applied successfully for the first time in displacement measurement of the Kashmir earthquake (2005).…”