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Professor John Tyrer,Professor of Optical Instrumentation
Loughborough University
‘Remote standoff imaging of explosive residue'
“When you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind” Lord Kelvin 1824-1907
Wolfson School of Mechanical and Manufacturing EngineeringLoughborough University LE11 4TU, [email protected]: +44 (0)1509 227531Fax: +44 (0)1509 227648
Fluorescence
Visible radiation is emitted from a substance when the excitation source is removedTypically within 10 -10 - 10 -3 sIf the emitted radiation lasts longer (can be seconds to days) this is phosphorescence
Fluorescence efficiency =fluorescent intensity/amount absorbedQuenching occurs when the fluorescence is inhibited by competing processesEnergy finds other routes to the ground state but without emitting optical radiation
The first fluorescent gated image of a fingerprint
5 nsec 15 nsec
17 nsec 20 nsec
Time base control allows fingerprint to be observed
Different pulse delay times, reveal fingerprint against paper fluorescence (1ns = 1 x 10-9sec)
Here the image is 30 nsecafter the laser firedthe paper is signal swamps the print
What do fabrics do?
Fluorescence Emission Spectra for Four Different Fabrics
0
200000
400000
600000
800000
1000000
1200000
350 400 450 500 550 600 650
Wavelength (nm)
Inte
nsity
(cps
)
White Cotton
White/Red/Green Cotton
White Knitted Cotton
Nylon
Fluorescence Emission Spectra for Low Intensity Fabrics
0
500
1000
1500
2000
2500
3000
3500
350 400 450 500 550 600 650
Wavelength (nm)In
tens
ity (c
ps)
Pale Green Patterned CottonDark Green Patterned CottonSilk75% Viscose,23% Nylon,2% LycraWool54% Polyester, 44% Wool, 2% Lycra50% Cotton, 50% PolyesterMohairAcetate
How about explosives?RDX Emission Spectra
0.00E+00
2.50E+05
5.00E+05
7.50E+05
1.00E+06
1.25E+06
1.50E+06
1.75E+06
2.00E+06
350 375 400 425 450 475 500
Wavelength (nm)
Inte
nsity
(cps
)
Semtex Emission Spectra
0.00E+00
5.00E+05
1.00E+06
1.50E+06
2.00E+06
2.50E+06
3.00E+06
3.50E+06
4.00E+06
4.50E+06
300 350 400 450 500 550
Wavelength (nm)
Inte
nsity
(cps
)
A Comparison between Semtex and White Cotton Emission Spectra
0.00E+00
5.00E+05
1.00E+06
1.50E+06
2.00E+06
2.50E+06
3.00E+06
3.50E+06
4.00E+06
4.50E+06
350 400 450 500 550 600
Wavelength (nm)
Inte
nsity
(cps
)
White CottonSemtex
Spectral Landscape of Sudan Red, colourant in Semtex
7
Red part of spectrumHence the name – Sudan Red
Colours and time base comparison
What is the imaging system capable of? Semtex PETN C-4
Broderie
‘Mohair’ Polar Fleece
Printed Poplin
Satin Jacquard - Emerald
Flannel
1st print of Semtex H
20th print of Semtex H
40th print of Semtex H
Semtex Residue on various components
Similar to a small
rucksack
Static Target System ERD‐ST
Explosive Residue Detection (ERD) typical use as screening system
ERD typical use as screening system
Notes:Hand‐held unit and/or swab system may also be used
Option to place at both sides ofgateway to check back and front
X‐ray detector
Passenger ERD
Explosives detector
Metal detectorgateway
Tensa Barriers Luggage ERD
ERDWand
Possible Airport Security Gateway
Support equipmentIn locked cabinet
TerminalEntrance
Wall or ceiling mounted detector head
Wall or ceiling mounted ‘CCTV’ style output from detector headVGA transmitter/receiverto extend screen cable lengthto reach display
Remote monitoringterminal (connectedvia network)
Notes:‐Multiple heads utilise multiple windows on the monitoring screen or alternativelyswitched selection, or alternativelydetection driven prioritised windows‐ Centralised evidence capture‐ Remote head monitoring
FREE FLOW
TerminalEntrance
Free Flow Entrance Ways
Option to place detector heads at both sides of the barriers to check back and front
Barriers
Remote monitoringterminal (connectedvia network)
Detector head
Detector head
Detector head
Multiple Access;- Underground, Airport, …
Thank you for listening
Any Questions?
John TyrerWolfson School of Mechanical and Manufacturing EngineeringLoughborough UniversityLE11 4TUUK
Tel: +44 (0)1509 227531Fax: +44 (0)1509 227648
