Incorporation of meshless scheme with contrast source inversion method for reconstructing dielectric objects

Contrast source inversion method (CSIM) is one of robust methods for reconstructing dielectric objects by integral equation approach. The method requires an intensive calculation of volume integrals over imaging domain in the optimization of cost functional and the process is very tedious. In this work, we incorporate a novel meshless scheme with the CSIM to simplify the calculation of volume integrals so that the reconstruction can be accelerated. The meshless scheme changes the volume integrals into boundary integrals through the Green-Gauss theorem when the integrands are regularized by excluding a small cube enclosing the observation node in the imaging domain. Numerical examples for reconstructing two contacting dielectric spheres are presented to illustrate the inversion approach and good results have been obtained.