TVmmC: Robust Calibration Method for Signal Distortion in Near-Field MIMO Imaging Radar

This paper proposes a robust calibration method for linear distortions in a wide-band system with two-dimensional near-field imaging capabilities. The proposed method, TVmmC, solves an optimization problem using total-variation regularization via the majorization-minimization approach in a 2D reconstructed image domain. The purpose of TVmmC is to remove the systematic frequency-dependent errors that are severe in many wideband systems. The novelty of TVmmC is to provide reliable calibration results even in the presence of clutter and noise, resulting in directly applying it in a real operating environment. To validate TVmmC, experiments were performed using a Ku-band imaging radar system that suffers from linear distortions in the radiofrequency subsystem. The radar system was tested in a real environment where clutter and noise were present, confirming that the application of TVmmC resulted in clear images.