Phase Unwrapping in the Presence of Scattering Nulls and Applications to Microwave Imaging

Q. Fang, P.M. Meaney, and K.D. Paulsen (USA)

Keywords

Microwave imaging, Phase unwrapping, Scattering nulls, Log-magnitude phase form

Abstract

Utilization of our log-magnitude/phase form (LMPF) iter ative reconstruction algorithm for microwave tomographic imaging has proven to be significantly more advantageous than the traditional complex form algorithm both in terms of solution convergence stability and the elimination of the need for a priori information in cases of large, high con trast imaging targets. However, for certain high contrast targets, the forward solution can often contain scattering nulls which complicate the phase unwrapping process nec essary in the LMPF algorithm and ultimately can cause in stability in the convergence behavior. We have developed a strategy for coping with these scattering nulls during the unwrapping process based on a theoretical understanding of their behavior. The image quality improvement is sub stantial compared with previous strategies.

Important Links:



Go Back