Generation and Calibration of High-Resolution DEM From Single-Baseline Spaceborne Interferometry: The "Split-Swath" Approach

The paper is focused on the main limits to the performances of the DEM retrieval from SAR interferometry, measured in terms of horizontal resolution and vertical accuracy. A mathematical model is developed to assess the accuracy of the location in 3D, given the two SAR images and a set of calibrated references, or Ground Control Point, with known accuracy, whereas we assume that the geometry of the interferometer, say the baselines, are known only at a very rough approximation. Simplified relations, used to compute the expected DEM retrieval accuracy, are derived and it is found that a two non-adjacent sub-swaths approach (the ’split-swath’ approach) improves the calibration efficiency. A numerical example, referring to a Ka-band single-pass interferometer, is also presented.