Persistent Scatterer Interferometry (PSI) inherently assumes a single temporally coherent scatterer inside a rangeazimuth resolution cell. This restriction leads to the rejection of numerous persistent scatterer (PS) candidates, particularly in urban areas where layovers occur frequently. Moreover, in case of high-rise buildings, it is necessary to compensate the phase associated with thermal expansion in an iterative way. It is worthwhile to approach tomographic techniques to address these

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... erns. SAR tomography has the potential to separate scatterers in elevation, thus resolving layover. Differential SAR tomography additionally allows retrieval of deformation parameters, including a possible thermal expansion term. In this paper, we investigate the combined use of SAR tomographic approaches and PSI for elevation and deformation estimation. Results are presented for an interferometric time-series of 50 TerraSAR-X stripmap images acquired over Barcelona city. Spatio-temporal inversion of scatterers along the façade of a high-rise building is presented as a special case.