1BL PU Ratio (Only 2BL) (Best) 1.000 0.994 0.970 0.950 0.920 0.900 0.800 0.700 0.500 0.000 (a) Final PU Ratio (Only 2BL) (Best) 1.000 0.994 0.970 0.950 0.920 0.900 0.800 0.700 0.500 0.000 (b) Figure 10. Success of the multi-baseline phase unwrapping correction. Green indicates consistency of phases and radargrammetry before (a) and after (b) the correction step in the Integrated TanDEM-X Processor. propagation effects are taken into account based on the same models as established in the TMSP. Additionally to the monostatic delay, which causes an altitude dependent offset corresponding to spatially varying location and height errors of typically 2-4 m [29], the differential tropospheric phase screen has to be accounted for as well. A few millimeters of differential propagation delay from slightly different viewing angles causes offsets of 1-3 m if not compensated [30]. 16 B. The Mosaicking and caliBraTion Processor (McP) After Raw DEM generation the last two steps for the production of TanDEM-X DEM products are the calibration of DEM acquisitions to reference heights (DEM calibration) and the mosaicking of single interferometric Raw DEMs into geocells (DEM mosaicking). Before DEM calibration incoming Raw DEMs are quality controlled and tie points and ground control points (GCPs) are extracted. DEM calibration requires a global ieee Geoscience and remote sensing magazine june 2014