ISAR add-on for focusing moving targets in very high resolution spaceborne SAR data

The work addresses the problem of focusing moving target in very high resolution Synthetic Aperture Radar (SAR) images. This task is here solved by using an Inverse Synthetic Aperture Radar (ISAR) add-on approach. The ISAR technique performs an autofocus procedure by implementing exhaustive search algorithms of functions based on image entropy or contrast. The algorithm discussed in this work is based on the re-use of autofocusing technique classically adopted in SAR focusing. The effectiveness of the proposed method is tested on COSMO-Skymed Spotlight SAR data of maritime targets.