Using long-time coherent scatterers in SAR data, called Persistent Scatterers (PSs), the deformation signal of objects can be measured from space. However, the nature of the corresponding image signatures is not known in detail. Methods focused on the simulation of highly detailed object models help to understand the origin of PSs. In this paper, simulated SAR data are geometrically linked to PSs for one test site. Thereafter, single PSs are selected and identified in the simulated 3D model. The case study indicates that a high number of PSs lack of geometrical correspondence to building features. Moreover, it is shown that the often observed occurance of PSs located below ground level is not due to processing errors but is a systematic effect caused by fivefold reflection.