Let's Do the Time Warp: Multicomponent Nonlinear Motion Estimation in Differential SAR Tomography

Kurzfassung

In the differential SAR Tomography (D-TomoSAR) system model the motion history appears as a phase term. In the case of nonlinear motion this phase term is no longer linear and, hence, can not be retrieved by spectral estimation. We propose the �time warp� method that rearranges the acquisition dates such that a linear motion is pretended. The multi-component generalization of time warp rewrites the D-TomoSAR system model to an M+1-dimensional standard spectral estimation problem, where M indicates the user defined motion model order and, hence, enables the motion estimation for all possible complex motion models. Both simulations and real data (from TerraSAR-X spotlight) examples demonstrate the applicability of the method and show that linear and periodic (seasonal) motion components can be separated and retrieved.