"Phase-Enhanced" 3D Snapshot ISAR Imaging and Interferometric SAR

Previously, a novel formulation for the generation of three-dimensional 3D inverse synthetic aperture radar ISAR images based on recent developments in high resolution spectral estimation theory was presented. Because this technique requires only snapshots of data, where a snapshot is defined as a block of Nyquist sampled frequency-time pulses of data, we refer to it as 3D snapshot imaging. Concomitant with these results, recent advances in interferometric SAR imaging have demonstrated the use of two-dimensional 2D range-Doppler image phase information to extract out-of-plane height information to obtain 3D images of ground scenes. In this case, a unique sampling grid is generated that allows overlaying of nearly identical 2D range-Doppler images and uses phase differences between these images to estimate the out-of-plane height information, from which a 3D image is developed. In this report, we develop a framework connecting these two techniques, particularly applicable to forming 3D images of target types typically dominated by smaller numbers 20 of scattering centers, and characterized by deterministic exoatmospheric motion having torque-free Euler dynamic spin and precession. Applications of the development are illustrated using simulation data specifically, the wideband, monostatic field is simulated using a simple point scatter model of a generic cone-like target, and the phase-enhanced 3D image is generated for differing cases. Extensions of the technique to bistatics are also discussed.