NDT for Anti-Terrorism Fighting

Vladimir V. KLYUEV, Alexey V. KOVALEV, Association “SPEKTR-GROUP”, Moscow, Russia

Abstract. The NDT methods provide efficient search of basic means used by terrorists (weapons, explosives and bombs, chemical and radioactive materials, counterfeit documents and money, etc.). The results of works done by “Spectrum –RII” on development of technical instruments and systems designed to solve tasks of search and observation, forensic analysis, all around the day and under any weather conditions surveys, etc. are discussed in the paper.

Introduction

One of the basic areas of “Spectrum-RII” activity is development and production of technical instruments, devices and systems for diagnostics and prevention of terrorist attacks and other criminal actions. The activity in this direction had been started in 1964 and became especially important and urgent during last 4 – 5 years. Nowadays the clear understanding of the directions of research works is formed thus make it possible to take leading positions in several segments of market offering the technical means for terrorism counterfighting. These segments cover following types of equipment: - Mobile and portable X-ray and X-ray TV units as well as visualization systems for them. - Non-cooled thermal vision cameras of various performances. - Optical (comprising broadband and multi channel) surveillance and observation means. - Endoscopic systems (fiber-optic, TV) of various performances. - Equipment for explosives detection (gas analyzers). - Equipment for forensic analysis.

1. X-ray systems

In developed mobile X-ray systems the following operating modes are implemented.

1.1 Dual energy digital radiography

Dual energy digital radiography provides detection of substances with different atomic numbers Z in examined objects. Developed working algorithm for dual energy radiography is based on variation of sounding radiation energy spectrum that makes it possible to detect in screened objects of potentially hazardous substances, for instance, narcotics and explosives. In Fig. 1 presented are results of initial image processing based on proposed algorithm. Examined objects are metal box with wall thickness 6mm and explosive simulator 30mm thick (both have same dimensions) as a result of screening two objects were distinguished as items of different categories – «metal» and «non metal».

ECNDT 2006 - We.3.5.4

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Fig. 1. Results of initial X-ray image processing.

1.2 Method of X-ray images cross-linking with simultaneous geometrical distortions correction

This technique is used in those cases when spatial resolution of used digital TV cameras is not enough to obtain required quality of lengthy or large square objects’ images. In Fig. 2 presented is example of forming from initial image of cross-linked one (2b) consisting of six shorts (2a). Proposed for this technique algorithm significantly improved the resolution of X-ray optic unit and eliminated geometrical distortions.

a) b) Fig. 2. Example of cross-linked image forming

Initial images obtained for two different energies

Processing algorithm

Images of two categories а) «metal» and

b) «non metal»

Criteria of image output. One category image displayed above the other one вывода

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2. Equipment based on thermal vision testing method

During last years a number of small size highly sensitive infra red (IR) imagers based on solid multi element non-cooled cores were developed. Designed to perform search and survey actions these instruments have wide functional capabilities. For example, a series of non-cooled IR-imagers based on bolometric matrixes generally called «Katran» were developed lately. In Fig. 3 presented the instrument itself and examples of its practical applications. In Table 1 given are technical parameters of produced models.

Fig. 3. IR-imager «KATRAN» and examples of images obtained with its help.

Table 1. Comparison table of technical parameters of IR-imagers of «KATRAN» series

Model KATRAN-1 KATRAN-2 KATRAN-3

Pixel count of array (resolution) 160х120 160х120 320х240 Spectral response, mcm 7-14 7-14 7-14 Thermal sensitivity, mK 100 60 50 Optional lenses Focal length (FOV)

8.5mm(350х500) 25mm (120х170)

5.8mm(500х370) 8.5mm(320х240) 11mm(250х280) 16mm(170х120) 25mm(110х80)

11.6mm/(500х37.50) 22.4mm(250х190) 45mm(120х90) 100mm(5.50х4.50)

Maximal distance of human being detection, m (focal length)

300 (25 mm) 840 (45 mm) 1600 (100 mm)

Weight with batteries, kg ≤0.9 ≤0.9 ≤1.5 Operating temperatures range, 0С -20 … +45 -20 … +45 -20 … +45

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Special features of IR-images of «KATRAN» series – high sensitivity, wide range of available optional lenses, light and convenient design along with robust casing, i.e. protection from external impacts, make it possible to use instruments on site.

3. Equipment based on optical (visual) method

3.1 Hidden optical objects detection

This method is used during development of instruments to detect hidden optic and electron-optical survey means (OSM). Between the last one sniper sights, night vision instruments, high aperture optics, video cameras for hidden surveys can be mentioned. The most efficient method of OSM detection is the laser radar one based on cat’s eye phenomena. When scanning the area of interest (where OSM are expected to be detected) by means of narrow guided ray the reflected radiation occurs and it propagates in the direction close to the direction of scanning beam incidence. In this case the OSM acts as cat’s eye providing forming of luminous spot-shaped catchlight. This method is implemented in two developed instruments:

1. The Instrument «ANTISVID -2» (Antiwatch) for detection of small size hidden TV cameras and other miniature light reflecting objects.

2. The instrument «SPIN-2» for detection of high aperture, long-focal-length optics at great distances.

In Fig. 4 presented is instrument «ANTISVID-2» designed for detection of small-sized objects at distances of up to 20m based on parallax-free optic scheme and able to detect hidden video cameras with lenses of «pinhole» type and aperture less than 1mm at pointed distances. While in Fig. 5 presented is result of its practical use, i.e. detection of hidden in the bag camera.

Fig. 4. General overview of instrument «ANTISVID-2»

Fig. 5. Detection of video camera with lens of pinhole type hidden in bag

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The instrument «SPIN-2» used at long distances (up to 1000m) to detect long-focal length optics presented in Fig. 6; while in Fig. 7 presented is result of its use for detection of sniper sight PO4x34 at distance 650m.

Fig. 6. General overview of instrument «SPIN-2»

Fig. 7. Detection of sight with the help of instrument «SPIN-2»

Some technical parameters of two above instruments are presented in table 2.

Table 2. Technical specification for «ANTISVID-2» and «SPIN-2»

Parameter ANTISVID-2 SPIN-2 1. Detection distance:

• Minimal, m • Maximal, m

2. Receiving channel field of view (HхV), deg. 3. Field of laser illumination pattern (HхV), deg. 4. Power supply, V DC 5. Continuous operation time, not less than, h 6. Dimensions, not more than, mm 7. Weight with battery, not more than, kg 8. Operating temperature range, 0C.

1.0

20.0 8х6 2х5

7 5

280х120х80 1.6

-10 … +45

5.0

1000.0 7х5 1х4

7 3

220х150х80 1.6

-10 ... +45

3.2 Multi channel systems

One more line of development of instruments and systems based on optical methods is engineering of wide band spectral multi channel systems («SPEKTR» series) for surveys and control actions. The functions and possibilities of such systems are determined by

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parameters and number of channels providing information acquisition. In Fig. 8 presented is one of the versions of above systems – three channel installation for survey and control «SPEKTR-3»; while in table 3 its technical parameters are given.

Fig. 8. General overview of system «SPEKTR-3»

Table 3. Technical parameters of «SPEKTR-3 » system

Types of registration channels

Basic parameters Multispectral and IR Thermal Optic-electronic

Operating spectral range (mcm)

0,35-0,5; 0,7-1,0; 1,1-1,7 (with thermo-electric cooling)

8-13

0,81 – laser emitter,

0,4 - 0,9 - receiver

Type and capacity of registering matrix (pixels)

1/2// CCD, 750х580 1// InGaAs, 320х256

1// pyroelectric,

320х240

1/2// CCD, 750х580

Matrix sensitivity 3*10-4 lux

Thermal sensitivity

0.10С

10-3 lux

Receiving lens type Transfocator 8 – 80mm, 17 – 1.8deg. /common for three

cameras /

Germanium 100mm/0.7 - 11deg.

Transfocator 8 – 80mm, 42 –

4.6deg. Dimensions /weight

of system (w/o tripod, tilt and power supply unit), not more than

540х350х270mm/12kg

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3.3 Endoscopic systems

Endoscopic systems also are part of instruments based on optical (visual) diagnostic method. In discussed case they are used as efficient search and observation means. Self-contained, monoblock fiber-optic endoscopes of series ETA (Fig. 9) comprise illumination module based on super bright LEDs and battery module where both are integrated in the endoscope casing. Such design makes it possible to considerably reduce instrument weight and dimensions and at the same time to increase time of continuous operation and improve ergonomic parameters. Similar approach was used during development of semi-rigid ETApzh (Fig. 10) and portable, monoblock TV- endoscopes of series ETV (Fig. 9) with LED power 3W. Positive results were achieved as well as for instruments of ETA series.

Fig. 9. General overview of self-contained (ETA) and TV (ETV) endoscopes.

Fig. 10. General overview of semi-rigid endoscopes

ETApzh.

The semi-rigid endoscopes ETApzh were purposely designed as they provide solution of number of tasks where flexible ones cannot be in practical use. In table 4 given are some technical parameters of endoscopes.

Table 4. Basic parameters of various series of endoscopes

Parameter ETA series ETV series Working part diameter, mm 4-10 6-12 Working part length, m 0.5-2.0 (2.5)м 2 м Distal tip articulation angle ±180° ±120° FOV 60° 40-60° Resolution 5 lines/deg. 320х240 pixels Illuminating source power, W 1 3 Power supply 4хАА dry cells 12 V DC Power consumption, W 1.2 10 Weight, kg 0,5-1 1.2 + 2.7 (illum. unit BOS-20)

Super small rigid endoscope (borescope) with working part diameter not more than 1mm (Fig. 11) was developed lately. In the working part of borescope combined are channels of image transmission and illumination. The working part can be rotated around longitudinal axe by 900 while eyepiece stays fixed.

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Fig. 11. Super small (diameter 1mm) borescope.

4. Equipment for explosives detection

The equipment for explosives detection is based on method of spectrometry of ion mobility in applied oscillating asymmetric field (so called transverse drift spectrometry). Enhancement of drift-chamber, use of modern materials, generator parameters optimization, implementation of precise electrometric amplifier with drastic signal digitizing, its preliminary processing and presentation in the from of ionogram with further processing and analysis make it possible to obtain results providing well raise of signal selectivity, interference immunity and equipment reliability. In Fig. 12 presented is instrument for explosives detection «KRON-VV» that registers explosives vapors present in the examined area. The basic technical parameters of this instrument, the number of detected explosives types, ability of their identification, examination results reliability, probability of false alarm, response and warm up time, method of information processing and presentation are significantly better than similar ones of analogs.

Fig. 12. General overview and practical use of instrument «KRON-VV»

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Typical ionograms of two types of often met explosives (TNT and NG) in combination with so called background ionogram, i.e. one obtained as a result of measurements in absence of explosives, are presented in Fig. 13 a&b. The captures presented to the right are results of simple deduction «signal-background». The evident peaks indicate presence of explosives in the examined area while peaks location makes possible the identification of registered explosives.

a)

b)

Рис.13. Ionograms obtained for two types of explosives (a – TNT; b – NG)

The «signal-background» deduction is the simplest methods of obtained results processing. Currently more sophisticated algorithms are developed; their use will improve screening reliability and explosives identification. These algorithms assume availability of: data base with various ionograms of different explosives; known dependences of ionogram types on atmospheric pressure, humidity and temperature. Algorithms implementation can provide explosives registration with reliability 0.998 and reduce number of false alarms up to level that does not exceed 0.002.

5. Equipment for forensic analysis

Important part of social security is verification of authenticity of various types of “economical” documents. For this task a number of instruments is developed that provide verification of documents, securities, bank notes, excise and special marks as well as reveal of any illegal corrections or falsifications of originals (scribing, additional writings not allowed corrections, washing and etching-out of initial performance details, replacement of document parts (separate pages or pictures), damage of seals integrity. Developed

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equipment makes it possible to reconstruct images occasionally or purposely hidden by inks or between glued pages, etc. In “Spectrum-RII’ several instruments and systems developed to solve above mentioned tasks. One of them is portable instrument for on-site documents and securities authenticity verification «Korund-MTV» presented in Fig. 14. It principle of operation is based on use of combination of two verification methods. One – visual examination of document illuminated by visible luminescent radiation, the second one – image examination in presence of reflected IR illumination, to provide such illumination two types of illumination sources are used – ultraviolet (UV) and infra red (IR).

Fig. 14. Instrument «KORUND-MTV» and its use.

In stationary conditions criminalistic complex for more detailed documents examination «Генетика-02.02» is used, Fig. 15. Practically all passport border check points at Russian airports are equipped with this complex. In the same picture presented is analog of above complex called «KORUND-TV».

Fig. 15. General overview of complex «GENETIKA -02.02» and set «KORUND-TV»

In Fig. 16 presented is distribution of metametric dye on authentic Russian note of 100 rubles and 500 euro note visible in reflected IR-radiation. Such distribution is used as sign of notes authenticity. In the same figure presented is example of high quality fake bank note of 100USD produced with use of authentic paper and having high polygraphic performance.

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Fig. 16. Examples of various banknotes authenticity verification with the help of complex «GENETIKA -02.02» and set «KORUND-TV»

Conclusions

The issues of public safety and security are of great importance nowadays. To prevent any negative actions in both social and economical areas society should be equipped properly. The problems generated by terrorist attacks and activities should be avoided and this can be done if proper preventive measures will be taken. Non-destructive testing for many years used for technical diagnostics and mostly used in industry now find wide area of application to provide not only industrial safety but public safety and security. More and more NDT methods known for long time and introduced in everyday life recently will be used and serve as basis for newly developed instruments for terrorism fighting.

a b b a

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