Multi-pass synthetic aperture radar for 3-D focusing

An overview is given on the possibility to achieve a 3-D, tomographic reconstruction of the illuminated area by using multiple passes of Synthetic Aperture Radar (SAR) system. This possibility is given in SAR interferometry by a non-linear processing that represents the simplest case of multi-acquisition. In particular, the Singular Value Decomposition (SVD) method is applied to get a "suitable" solution, able at managing the uneven track distribution and to properly account for any a-prior knowledge about the support of the object function to increase the resolution limits.