Influence of surface of explosive on its detection and identification using the SDA method for analysis of the reflected THz signal

2014

SPIE Proceedings

Self Cite

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

Section: Reflected Rdx Signalsupporting

confidence: 72%

Section: Modified Integral Correlation Criteriamentioning

confidence: 99%

Section: Introductionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

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

2014

SPIE Proceedings

Self Cite

Possibility of the detection and identification of substance at long distance using the noisy reflected THz pulse under real conditions

Terahertz Physics, Devices, and Systems IX: Advanced Applications in Industry and Defense

2015

Self Cite

We show possibility of the detection and identification of substance at long distance (several metres, for example) using the THz pulse reflected from the object under the real conditions: at room temperature and humidity of about 70%. The main feature of this report consists in a demonstration of the detection and identification of substance using the computer processing of the noisy THz pulse. Amplitude of the useful signal is less than the amplitude of a noise. Nevertheless, it is possible to detect "fingerprint" frequencies of substance if these frequencies are known and the SDA method is used together with new assessments for probability estimation for presence of detected frequencies. Essential restrictions of the commonly used THz TDS method for the detection and identification under real conditions (at long distance about 3.5 m and at a high relative humidity more than 50%) are demonstrated using the physical experiment with chocolate bar and thick paper bag. We show also that the THz TDS method detects spectral features of dangerous substances even in the THz signals measured in laboratory conditions (at distance 30-40 cm from the receiver and at a low relative humidity less than 2%); the n-Si and p-Si semiconductors were used as neutral substances. However, the integral correlation and likeness criteria, based on SDA method, allow us to detect the absence of dangerous substances in the samples. Current results show feasibility of using the discussed method of the THz pulsed spectroscopy for the counter-terrorism problem.

Efficiency of using the spectral dynamics analysis for pulsed THz spectroscopy of both explosive and other materials

2015

SPIE Proceedings

Self Cite

One of the modern problems arising in the detection and identification of substances is a development of criteria for the assessment of a presence of explosive (or other dangerous substance) fingerprints in THz signals transmitted through or reflected from a sample. Obviously, criteria depend on the method used for the substance detection and identification. Taking into account our previous experience, we use for a solution of this problem the SDA method (method of the spectral dynamics analysis). Essential restrictions of usually used THz TDS method for the detection and identification under real conditions (at long distance about 3.5 m and at a high relative humidity more than 50%) are demonstrated using the physical experiment with paper napkins and thick paper bag. We show also that the THz TDS method detects spectral features of dangerous substances even in the THz signals measured in laboratory conditions (at distance 30-40 cm from the receiver and at a low relative humidity less than 2%) with semiconductors of different types used as samples. However, the integral correlation criteria, based on SDA method, allows us to detect the absence of dangerous substances in semiconductors. In order to demonstrate the possibilities of the integral criteria for finding additional substances in the mixture with semiconductors, we modeled several mixtures of n-doped Silicon with neutral substance Soap in different ratio. The discussed algorithms show high probability of the substance identification and a reliability of realization in practice, especially for non-destructive testing and security applications.