Experimental Demonstration of the Shadow Projection Algorithm for Near-Field Microwave Imaging of Buried Objects in Layered Media

Abstract

A shadow projection algorithm for near-field microwave imaging has been introduced to distinguish the size of objects hidden in the layered structure. For an external source, the radiated energy is focused into the normal direction due to the lensing effect caused by refraction at the boundary between free space and the first layer. The lensing effect is utilized to form the shadow of the buried objects on the rear interface, which provides more accurate object size and shape than a conventional image. The efficacy of the shadow projection approach is validated with measurements of multiple objects embedded in stratified media.