Distinguishing between materials in terahertz imaging using wide-band cross ambiguity functions

Terahertz pulsed imaging is a novel imaging technique whereby sub pico-second broadband THz pulses are used in the analysis of samples, through transmission and reflection modalities. This paper briefly introduces terahertz pulsed imaging and its potential medical applications, before exploring how wavelet analysis may be used in categorising terahertz imaged samples, specifically the use of the terahertz reference pulse as a mother function through wide-band cross ambiguity functions. We show that analysis using ambiguity functions can distinguish between a nylon and a resin step wedge phantom, and furthermore that the results obtained are consistent with those of traditional time domain and Fourier based techniques. (C) 2004 Elsevier Inc. All rights reserved.