Multi-aspect Aperture Synthesis for 3D Radar Imaging: A Review.

Synthetic aperture radar (SAR) 3-D imaging technique can eliminate severe layover and geometric distortions in 2-D images, which greatly facilitates target recognition and 3-D modeling. However, due to the strong anistropic scattering properties of man-made targets, it's hard to obtain high-resolution 3-D images by conventional SAR imaging methods. Multi-aspect aperture synthesis is an advanced SAR imaging mode, which is used to obtain the multi-aspect anisotropic scattering information as well as the 3-D structures of the observed targets. We demonstrate that this technology greatly facilitates the 3-D SAR imaging of complex-structured targets. In this article, we introduce several recent works of our research group on 3-D radar imaging based on multi-aspect aperture synthesis techniques. Main topics include multi-aspect SAR 3-D imaging modes, spatial resolution theory, an object-level 3D reconstruction method with single-channel single-pass SAR data, theory of holographic SAR tomography imaging technology and a corresponding 3D inversion method, and an interferometric circular SAR 3D reconstruction method with its experimental results on the FAST radio telescope data. We analyze the advantages and existing scientific problems for each proposed technical path in detail, aiming to provide new solutions for SAR 3D imaging/inversion problems. [ABSTRACT FROM AUTHOR]