Back-Projection Tomography with Polarimetric HoloSAR data and Sub-aperture Processing.

Digital surface models (DSMs) are sets of elevation data of the Earth's surface useful for urban studies representing height estimation of buildings. They can be derived from a set of synthetic aperture radar (SAR) images acquired in an interferometric (InSAR) or tomographic configuration (TomoSAR). More informative DSMs can be obtained by exploiting polarimetric TomoSAR data acquired in spotlight mode with a circular flight path. This configuration, referred to as polarimetric holographic SAR (HoloSAR) allows one to obtain DSMs with a high point density and 360-degree information of the objects. In this work, we present steps for deriving DSMs with polarimetric HoloSAR data by means of a time domain back-projection algorithm (TDBP) and sub-aperture processing. Performance analysis showed that the resulting DSM is more similar to an equivalent LiDAR-based reference DSM in comparison to those derived with single-aspect or single-polarization data.