In our contribution we present an initial assessment of the applicability of TerraSAR-X for repeat-track interferometry. A series of TerraSAR-X repeat observation in stripmap mode over an test site that includes different landuse classes as well as fast and slow deformation phenomena was selected for our investigation. From our investigation we conclude that longterm interferograms can mainly be interpreted over urban areas. For forested areas and for denser agricultural vegetation such as fully grown crops the coherence levels are very low even for 11 day intervals. For sparse vegetation as present in late winter the coherence is high, over many fields even over several 11-day cycles. The high spatial resolution is ideal to measure localized deformation patterns. For slow deformation at larger scale confusion with atmospheric effects is strong. Multi-temporal approaches can be used to resolve the deformation and atmospheric phase components if sufficient numbers of observations are available.