Point Cloud and 3-D Surface Reconstruction Using Cylindrical Millimeter-Wave Holography

Different from conventional millimeter-wave (MMW) holographic 3-D imaging, a new technique that can produce accurate point cloud and the 3-D surface model of the target based on a cylindrical MMW holography system is proposed. The precision of the obtained model is much higher than the resolution of the 3-D image since the phase information in the echoes is utilized more sufficiently. Compared with some optic-based point cloud and 3-D surface reconstruction methods, the proposed method is independent of the ambient light conditions and is capable to penetrate clothes and wrappers. An overall processing framework is first presented. Subapertures and the cylindrical-to-planar wave transformation technique are used to split the whole cylindrical aperture into several equivalent planar subapertures. Then, an enhanced frequency interferometry method is proposed to reconstruct the depth maps of the target from different views. Finally, the integrated point cloud and 3-D surface model is obtained by merging all the subaperture results. A series of numerical simulations and a proof-of-concept experiment are carried out. Both the simulation and experimental results validate the effectiveness and show the superiority of the proposed method.