Analysis of The Performance of The NOSM For High Contrast Targets

Abstract

Electromagnetic inverse scattering from high con-trast scatterers is of special importance, especially in MicrowaveImaging, wherein the recent technology aims to image highcontrast scatterer. To this purpose, this paper presents an analysisof the performance of the recently proposed microwave imagingtechnique of the Near Field Orthogonality Sampling (NOSM)for the high contrast targets. For this purpose, the indicator ofthe NOSM, which is the reduced scattered field, is derived foran electrically homogeneous circular scatterer, which is centeredaround origin. Next, the ratios of the indicator energy densitiesinside and outside of the target is defined as a quality metric.After, the quality metric and its expressions for limiting cases(i.e. where the electrical parameter of the the target is toolarge or too low) are derived in terms of the background’sand target’s electrical properties. Then, the introduced metricis computed and plotted for a popular application, which ismicrowave imaging of the breast. Obtained results show thatthe high contrasts between the target and the background doesnot have an important affect on the quality of the reconstructionsof the NOSM.