  The reconstruction of physical properties of a medium from boundary
measurements, known as inverse scattering problems, presents significant
challenges. The present study aims to validate a newly developed
convexification method for a 3D coefficient inverse problem in the case of
buried unknown objects in a sandbox, using experimental data collected by a
microwave scattering facility at The University of North Carolina at Charlotte.
Our study considers the formulation of a coupled quasilinear elliptic system
based on multiple frequencies. The system can be solved by minimizing a
weighted Tikhonov-like functional, which forms our convexification method.
Theoretical results related to the convexification are also revisited in this
work.
