An Image-Domain Filter for Refraction Effects Compensation of Penetrating MIMO Imagery

Autofocusing of multiple-input and multiple-output (MIMO) penetrating radar is a recent developing method to solve the problem of image focusing problem in unknown environment. However, the ergodic search process in the subfocusing process greatly increases the amount of calculation, which limits the application of this method in practice. To solve the problem, we introduce an image-domain-filter-based method. All the compensation and correction are based on image domain, and it avoids calculating the position of the refraction point, which saves much time of computation. In this letter, we prove the image filter can autofocus well in both ground penetrating and wall penetrating scenarios under circumstances with unknown parameters. Both the simulation and the measurement experiments show the method can complete the compensation precisely and quickly and offers better focusing quality.