Circular SAR motion compensation using trilateration and phase correction

Circular SAR (CSAR) has raised an increasing interest in recent years. As a new SAR imaging mode, it has the ability to achieve sub-wavelength resolution for isotropic targets on planar ground and 3-D reconstruction^[1]. However the high resolution depends on high accuracy of platform position. For CSAR systems operating at centimeter wavelength, cm-level accuracy Position and Orientation Systems (POS) couldn´t fulfill the requirements. Motion compensation is the key technique to obtain focused CSAR images. In this paper, we propose a method for CSAR motion compensation based on echo data which does not rely on high precision POS .It combines trilateration and phase correction. Calibrators are used to help reconstructing flight trajectory. The approach is validated via simulation.