ABSTRACT
The targeted accuracy of the global DEM generated in the context of the TanDEM-X mission follows the High-Resolution Terrain Information 3 (HRTI-3) specifications. The elevation product will be provided in geographic coordinates. The grid spacing is 0.4 arcsec in latitude and longitude corresponding to a ground resolution of ~12 × 12 m. The longitude spacing is varied every 10° beginning at 50° and every 5° from 80° to 90° in order to compensate for the convergence of the meridians at the poles. Hence, the coarsest spacing is 4 arcsec between 85° and 90° latitude. In the TanDEM-X mission, the TerraSAR-X and TanDEM-X satellites record data in the single-polarized StripMap mode with a resolution of 3.3 m in azimuth and 1.2 m in range. Depending on the incidence angle, the range resolution converts into 3.0-3.5 m ground resolution (Eineder et al., 2010). The position of the strip acquired during the second acquisition phase (2012/2013) is shifted by approximately 50% compared to the first year (2011/2012).
