Dual-Probe Probe- and Phase-Compensated Reflection-Coefficient-Only 3-D Microwave Holographic Imaging

A probe- and phase-compensated 3-D microwave holographic imaging algorithm based on dual-probe scanning setup and using only the reflection coefficients is proposed. It is extended from the one based on single-probe setup, in which an auxiliary equation must be used to ensure a reasonable numerical stability. The difference between the algorithms is discussed first, and then the numerical stabilities are investigated qualitatively and quantitatively. It is shown that the numerical stability of the dual-probe imaging algorithm is dominated by the reflection coefficients and that the contributions of transmission coefficients to numerical stability as well as the image quality are negligible. Moreover, the condition number of the proposed dual-probe reflection-coefficient-only imaging algorithm is equal to that of the single-probe algorithm exploiting the auxiliary equation. This implies that the lossless assumption imposed by the auxiliary equation can be discarded in the proposed dual-probe algorithm. Therefore, the proposed algorithm is also feasible for imaging lossy dielectric targets at no extra computational cost. Lastly, for verification, a series of images reconstructed from the simulated scattering data are presented.