Generalized Three-Dimensional Imaging Algorithms for Synthetic Aperture Radar With Metamaterial Apertures-Based Antenna

Due to the flexibility in system design and small form factors, frequency-diverse imaging regime gained popularity in recent millimeter-wave (MMW) computational imaging (CI) research trends. In principle, frequency-diverse imaging systems produce the pseudorandom and spatially variant radiation fields to interrogate spatial information and reconstruct scene images using computational algorithms. Specifically, artificially structured metamaterials apertures antennas (MAA) have gained traction for their ability to manipulate electromagnetic waves in a deliberate and controlled manner. Combined with synthetic aperture radar (SAR) technologies, by moving a linear shape MAA in crosswise direction, fully three-dimensional (3D) scene images could be obtained through antenna motion. Focusing on the peculiar imaging geometry, we propose two kinds of postprocessing algorithms to black achieve 3D scene images reconstruction. The crux of the post-processing algorithms rely on the decoupling between cross-range dimension and antenna platform direction in the imaging domain, allowing the scene to be partitioned into a number of cross-range slices and reconstructed in a parallel manner. Compared with the traditional image reconstruction algorithms in frequency-diverse imaging, the proposed algorithms are more efficient and could effectively achieve 3D scene space observing. The extensive imaging simulations are conducted to verify the effectiveness of the proposed algorithms.