Combined Use of the Modified Born and Rytov Approximations in NonIterative Microwave Inverse Imaging With Dominant Current

ABSTRACT The Born approximation (BA) and Rytov approximation (RA) are common in solving electromagnetic inverse scattering problems (ISPs). However, purely applying these approximations only yields rough inversion results. To this end, a noniterative combined modified method using the real part (CMM‐R) is presented to extend the limitation in accuracy and effectiveness encountered by traditional Born/Rytov‐based approaches. Based on the connection between modified RA (MRA) and modified BA (MBA), the complementary strengths of MRA and MBA are integrated. Specifically, these two modified inversion methods are implemented by employing the dominant current, whereas only the real part of MRA is used to mitigate phase wrapping issues. The simulation and experimental results demonstrate that the proposed CMM‐R achieves higher accuracy than traditional modified Born/Rytov‐based methods for imaging mild scatterers. As a noniterative method, CMM‐R provides a robust initial guess for further iterative algorithms.