ISAR for concealed objects imaging

Abstract

A new promising architecture of microwave personnel screening system is analyzed in this paper with numerical simulations. This architecture is based on the concept of inverse aperture synthesis applied to a naturally moving person. The extent of the synthetic aperture is formed by a stationary vertical linear antenna array and by a length of subject's trajectory as he moves in the vicinity of this antenna array. The coherent radar signal processing is achieved by a synchronous 3D video-sensor whose data are used to track the subject. The advantages of the proposed system architecture over currently existing systems are analyzed. Synthesized radar images are obtained by numerical simulations with a human torso model with concealed objects. Various aspects of the system architecture are considered, including: advantages of using sparse antenna arrays to decrease the number of antenna elements, the influence of positioning errors of body surface due to outer clothing. It was shown that detailed radar images of concealed objects can be obtained with a narrow-band signal due to the depth information available from the 3D video sensor. The considered ISAR architecture is considered perspective to be used on infrastructure objects owing to its superior qualities: highest throughput, small footprint, simple design of the radar sub-system, non-required co-operation of the subject.