Nonlinear Subsidence Rate Estimation Using Permanent Scatterers in Differential SAR Interferometry
Fong-Min Chou
Abstract
Geophysical applications of radar interferometry (differential synthetic aperture radar interferometry, DInSAR) calculate the interference pattern caused by the difference in phase between two images acquired by a spaceborne synthetic aperture radar at two distinct times. While conventional InSAR has proven very effective in measuring deformation in regions of good coherence, it is clear from almost any volcano interferogram that there are large areas on most volcanoes where signals decorrelate and no measurement is possible.
Temporal and geometrical decorrelation often prevents SAR interferometry from being an operational tool for surface deformation monitoring and topographic profile reconstruction. Moreover, atmospheric disturbances can strongly compromise the accuracy of the results. In this paper, we present a complete procedure for the identification and exploitation of stable natural reflectors or permanent scatterers (PSs) starting from long temporal series of interferometric SAR images. When, as it often happens, the dimension of the PS is smaller than the resolution cell, the coherence is good even for interferograms with baselines larger than the decorrelation one, and all the available images of the ESA ERS data set can be successfully exploited. Anew approach to the estimation of the atmospheric phase contributions, and the local displacement field is proposed based on simple statistical assumptions. New solutions are presented in order to cope with nonlinear motion of the targets. We discuss the use of PS in urban areas, like Pomona, CA, showing subsidence and absidence effects andshown of small motion measurements, DEM refinement, and APS estimation and removal in the case of a sliding area in Ancona, Italy. ERS data have been used.
Reference
Alessandro Ferretti, Claudio Prati, and Fabio Rocca, Nonlinear subsidence rate estimation using permanent scatterers in differential SAR interferometry, IEEE transactions on geoscience and remote sensing, vol.38, no.5, September 2000
Alessandro Ferretti, Claudio Prati, and Fabio Rocca, Permanent scatterers in SAR interferometry, IEEE transactions on geoscience and remote sensing, vol.39, no.1, January 2001
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