UAV-SAR Panoramic 3D Imaging for Urban Area: A Multi-angle Tomography Approach

Tomographic synthetic aperture radar (TomoSAR) three-dimensional (3D) imaging technology solves the layover problem in SAR imaging, and has broad application prospects in urban areas by virtue of the flexibility of unmanned aerial vehicle (UAV) platform. However, the occlusion of urban buildings causes serious shadow problems, resulting in the loss of 3D structures of urban areas. At the same time, the nonlinear signal processing algorithms in TomoSAR further aggravate the loss of scattering information. Aiming at the above problems, a multi-angle TomoSAR 3D imaging method is proposed in this paper to realize panoramic 3D imaging in urban areas. The proposed method combines the advantages of TomoSAR imaging and back projection (BP) algorithm. Firstly, the 3D structures of urban areas can be accurately reconstructed by TomoSAR imaging, becasue of its advantage of achieving super-resolution. Then, geometric positioning is used to achieve the accurate fusion of multi-angle 3D structures. Finally, BP algorithm is used to obtain the lossless scattering information because of its advantage of high fidelity, so as to realize panoramic 3D imaging. The effectiveness of the proposed method is verified by multi-angle TomoSAR simulations based on UAV SAR parameters.