A method for the automatic characterization of InSAR atmospheric artifacts by correlation of multiple interferograms over the same site

Theoretically SAR interferometry allows for the extraction of very precise digital elevation models (DEM) with a potential accuracy of a few meters (3 m rms or better for ERS), as well as for the determination of ground displacements with a centimeter level accuracy in the case of differential interferometry. In practice, the presence of atmospheric fringes limits the confidence in the results. Varying atmospheric conditions between the two acquisitions induce a path difference generating InSAR artifacts that cannot be corrected if only one interferogram is available. However, if an interferometric triplet (three interferometric pairs based on three different radar acquisitions over the same site) can be formed, the atmospheric artifacts related to each date can be characterized by correlation, the objective being to subsequently filter them out