Effective criteria developing for the identification of substance using the reflected THz signal

Abstract

We propose and discuss modified correlation criteria for the detection and identification of dangerous substances using pulsed THz signal in the reflection mode. These criteria are integral criteria in time and they are based on the SDA method. We develop various approaches for enhancement of features of a detecting substance in reflected THz signal under investigation. These criteria are applied for the detection of different explosive situations. Among them we consider a mixture of explosives and PWM C4 explosive with very complicated surface. Proposed algorithms show both high probability of the substance identification and a reliability of realization in practice. We discuss modified correlation criteria for the detection and identification of dangerous substances using pulsed THz signal in the reflection mode.Keywords: reflected THz pulse, method of spectral dynamics analysis, detection and identification of substances, modified integral correlation criterion. *vatro@cs.msu.ru; phone 7 495 939-5255; fax 7 495 939-2597

High effective time-dependent THz spectroscopy method for the detection and identification of substances with inhomogeneous surface

“…Obviously, these parameters must coincide for both dynamics and . In the current paper, as in our previous articles [ 32 ]-[ 38 ], these parameters were chosen as follows: the window length T = 2.8 ps, its shift Δ = 0.2 ps.…”

“…Earlier in [ 27 ]-[ 29 ] we demonstrated the possibility of using the SDA-method for the detection and identification of various neutral and dangerous substances in the transmission and reflection mode at short (no more than 30 cm) distances. In [ 30 ]-[ 32 ] we proposed to use for this purpose the ICC together with the SDA-method. In [ 33 – 35 ], the spectral properties of THz pulses measured at long distances of about 3.5 meters and at non-zero humidity were investigated by means of the ICC.…”

“…The detection and identification of different types of explosives and illicit drugs by means of the SDA-method together with various types of the ICC is described in a number of our previous papers. Thus, in [ 32 ] the SDA-method together with the first types of the ICC was applied for the detection and identification of explosives RDX, HMX, PETN and two mixtures of explosives with three components each in reflection mode. The approach discussed in the current paper was successfully applied in [ 36 ], [ 39 ] for the detection and identification of illicit drugs MA, MDA, MDMA in very noisy THz signals as well as for detection of explosive HMX absorption frequencies in the THz signal reflected from the pellet with a smooth surface.…”

A Possible Way for the Detection and Identification of Dangerous Substances in Ternary Mixtures Using THz Pulsed Spectroscopy

“…Earlier in References [37,38,39], the SDA-method was used for the detection and identification of various substances in the transmission and reflection mode at a short (no more than 30 cm) distance between the receiver and an object under investigation. In References [40,41], we proposed using of the ICCs together with the SDA-method to achieve the detection with high probability. In References [42,43,44], the ICCs were applied for the substance detection and identification at long distance of about 3.5 meters under real conditions, which cause the highly noisy THz signal [45,46,47].…”

“…In Reference [41], for the detection and identification of the ternary mixtures, mentioned above, we used one of the first types of the ICC, which takes into account the spectral brightness of the absorption frequencies of both the standard THz signal and the THz signal under investigation. The identification was carried out using the first sub-pulse only considering the main pulse reflected from the sample, as well as the remote part of the signal.…”