Range Resolution Enhancement for Three-Dimensional Millimeter-Wave Holographic Imaging

In three-dimensional (3-D) millimeter-wave (MMW) holographic imaging, high cross-range resolution images can be achieved by synthetic aperture technique. However, the low range resolution that is always limited by the system bandwidth may cause the range profile discontinuous. To overcome this limitation, we present a range resolution enhancement (RRE) algorithm to reconstruct 3-D MMW images with high resolution in both the cross-range and the range domain. The proposed RRE algorithm explores the prior continuity of the target and utilizes the phase unwrapping-based method to retrieve the range-related phase, which can be directly converted into a fine range distribution. Simulation and experimental results show that RRE can give a continuous and smooth range profile that is corrupted into stair-like patches in the conventional range migration algorithm.