A Novel 3-D Imaging System for Buildings Using Millimeter-Wave Dual-Antenna SAR With Rotation

Three-dimensional synthetic aperture radar (SAR) imaging holds significant potential for the health monitoring of buildings, as it can resolve the geometric distortion present in typical 2-D SAR images. This article introduces a novel 3-D imaging technique based on a dual-antenna Interferometric rotating SAR (RSAR) (Interferometric RSAR) mode. Our proposed method uses the center of a straight track as the rotation center, collecting data from two distinct angles in one rotation simplify data acquisition. The main innovation is the first use of the multiangle 3-D imaging capabilities of RSAR to resolve the height ambiguity issue caused by interferometric measurements. This strategy enables the accurate determination of ambiguity numbers and reconstructs of high-precision 3-D point cloud. Additionally, we analyze the 3-D imaging capabilities of the proposed method from both the image domain and the k-space perspective, offering detailed insights into its theoretical foundations. Finally, a real-world millimeter-wave (mmW) dual-antenna radar experiment validates the proposed method, achieving an accuracy of 0.1874 m compared to LiDAR.