A processing driven approach to airborne multi-baseline SAR tomography

In this paper we discuss 3D tomographic techniques for processing airborne SAR data acquired from largely irregular trajectories. The discussion is based on the L-Band data-set acquired over the Mittelbergferner glacier in 2014 in the frame of the ESA campaign AlpTomoSAR. Signal focusing is based on Time Domain Back Projection (TDBP), concerning the generation of both 2D SLC data stacks and 3D Tomographic data cubes, as this approach allows to correctly cope with random trajectory deviations, as well as with range and azimuth shifts depending on focusing height. Data Phase Calibration is also considered, in order to recover phase screens due to an imperfect knowledge of flight trajectories.