Non-Linear Least Squares Algorithm for Detection of Simple and Double Persistent Scatterers

Abstract

Synthetic Aperture Radar (SAR) Tomography is a multi-temporal technique which can reconstruct the 3D profile of a scene. One of its main features consists in the ability to detect the presence of multiple Persistent Scatterers (PS) within the same resolution cell. This paper aims to investigate the super-resolution capabilities of SAR Tomography, by detecting targets situated at a distance which is close to Rayleigh resolution. Elevation positions of scatterers are determined with Capon estimation, which is characterized by higher side-lobs reduction. An adapted form of multi-looking is proposed for extraction of targets contribution from reconstructed reflectivity functions and for estimation of reflectivity power textures. An algorithm for detection of dominant and secondary PSs will be conducted based on the derived reflectivity estimates, trying to preserve the advantages of Capon filtering used for reflectivity reconstruction.