A Fast and Super-Resolution Method of Vortex-Based Imaging

With characteristics of particular wavefronts and orthogonal modes, the sparse imaging method based on the vortex waves could obtain high-resolution reconstruction. However, building a large-scale observation matrix is time-consuming and heavily burdens the whole imaging procedure. Inspired by the spherical harmonic expansion of plane waves, this letter provides a fast super-resolution imaging method based on the vortex waves. Featuring spherical harmonic functions and a transformation, an orthogonal matching pursuit algorithm for high-resolution imaging exploits a low-rank matrix decomposition of the observation matrix. Simulation results show that the proposed method exhibits significant efficiency advantages while retaining high resolution, achieving an efficiency of up to 51.4% when applied to a large-scale observation matrix.