On Algorithms Based on Joint Estimation of Currents and Contrast in Microwave Tomography

TL;DR

This paper proposes two improved algorithms for microwave tomography that enhance the contrast source inversion method by utilizing advanced conjugate gradient techniques for more robust and efficient imaging.

Contribution

The paper introduces two novel algorithms based on conjugate gradient methods that improve the robustness and efficiency of contrast source inversion in microwave tomography.

Findings

Both algorithms outperform the original contrast source inversion in efficiency.

The second algorithm achieves simultaneous updates, reducing computation time.

Improvements are demonstrated through comparative analysis.

Abstract

This paper deals with improvements to the contrast source inversion method which is widely used in microwave tomography. First, the method is reviewed and weaknesses of both the criterion form and the optimization strategy are underlined. Then, two new algorithms are proposed. Both of them are based on the same criterion, similar but more robust than the one used in contrast source inversion. The first technique keeps the main characteristics of the contrast source inversion optimization scheme but is based on a better exploitation of the conjugate gradient algorithm. The second technique is based on a preconditioned conjugate gradient algorithm and performs simultaneous updates of sets of unknowns that are normally processed sequentially. Both techniques are shown to be more efficient than original contrast source inversion.