Identification of explosive media using spectrum dynamics under the action of a THz pulse

Abstract

ABSTRACT A method of THz spectral dynamics analysis (SDA) of medium response in the THz and GHz ranges, which was devel-oped by us in previous papers for detection and identification of materials, is used for the treatment of experimentally measured signals, passed through selected explosives, including those hidden under covering materials. This technique is based on the window sliding method and on restoration of the TH z pulse. It allows researchers to follow the dynamics of many spectral lines in one set of measurements simultaneously and to obtain the full information about the spectrum dy-namics of the THz pulse. Relaxation time of rotational transiti ons, for example, can be determ ined too. This information gives an opportunity to detect and identify materials despite the similarity in their THz spectra - which may be identical. We show that the spectrum dynamics of THz pulses, passed through the explosives hidden under plastic, cotton and leather barriers – covers, differ widely fo r these media despite little difference in their spectra. Consequently, our method allows for detection and identification of the hidden explosives with high probability. Keywords: spectrum dynamics of medium response, detection and identification of explosives, THz pulse with a few cycles.