Ultra Wide Band Tomography – Experimental Hardware and Image Reconstruction

M. Bilal1, W. Yin1, M. Z. Abdullah2, D. W. Armitage1 and A. J. Peyton1

1 School of Electrical and Electronic Engineering, The University of Manchester, UK, Email: Muhammad.Bilal@postgrad.manchester.ac.uk

2 School of Electrical and Electronic Engineering, Universiti Sains Malaysia, Penang, 14300, Malaysia

ABSTRACT

Ultra wideband (UWB) electromagnetic tomography (EMT) is based on the propagation of ultra fast EM impulses, through the object space. The spatial resolution of the technique is determined in part by the pulse duration, which is typically from hundreds of ps to few ns, with corresponding pulse lengths in the mm-to-cm range. Applications require suitable dielectric target material through which the UWB impulses can propagate without excessive attenuation or dispersion. These applications include industrial (e.g. plastic processing, timber, feedstock delivery, food processing etc.), environmental (cross bore hole radar and ground penetrating radar GPR are already widely used) and medical (detectable pulses can travel sufficient distances through biological tissue, which has a wide permittivity contrast at these frequencies) ones. The field is subjected to some research and most systems are at the experimental stage.

The aim of this paper is to present an experiment UWB tomography system. The system contains two antennas for transmission and reception respectively and operates by mechanically scanning the transmitter and receiver assemblies. This paper will describe the operation of the system and the associated UWB component blocks. Results showing the propagation of pulses through different target material will be presented, along with the first images based on measured results from phantoms. The operation of the system has also been modelled with 2D and 3D propagation codes, which will also be reported briefly. Image reconstruction will be discussed in a sister paper on the forward and inverse problems.

The paper will conclude with a look forward to the future developments and possible applications of this emerging technology.

Keywords Ultra Wideband, Microwave Tomography, Electromagnetic Tomography, Experimental