Velocity field retrieval from long term coherent points in radar interferometric stacks

This paper addresses the question of how to robustly estimate linear deformation at a large number of points from differential phase in an interferometric stack. The so-called "Permanent Scatterers technique" (Ferretti et al. 2001), uses a relatively large number of differential interferograms of the same area, co-registered at the same master SLC image. Linear deformation rates and DEM errors are estimated for pixels that have limited temporal decorrelation. This straightforward and generic setup has been used in a network approach that uses connections between nearby points to compute a velocity field for large areas.