INL TECHNOLOGIES

National Security

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Concealed Weapons Detection

Using a magnetometer-based portal to detect potential threats

The CWD portal accurately

pinpoints the location, size

and number of concealed

weapons while

differentiating personal

artifacts such as coins, keys

and belt buckles.

Revealing

Multiple Networked CWD

systems controlled via central

monitoring station

A Weapons Detection

Solution

Terrorists, both domestic and

foreign, are introducing new

and emerging threats in the

smuggling of weapons

through security checkpoints.

To address these threats, INL,

through the support of the

National Institute of Justice,

developed a portal-style

concealed weapons detection

system that uses passive

magnetic sensors. The system

provides a non-intrusive

method for rapid detection,

location, and archiving of data

– including visual data – of

potential suspects and weapon

threats.

Method of Operation

The Concealed Weapons

Detector (CWD) senses

disturbances in the ambient

earth’s magnetic field –

disturbances such as those

caused by a weapon passing

through the aperture of the

portal. The CWD uses sixteen

magnetic gradiometer sensors

arrayed on both sides of the

portal aperture. Data are

collected from each of the

gradiometers, and the change

in the magnetic field over

ambient background is

determined. An overall

response is derived and the

CWD sensors are processed

as a group to determine the

location and size of detected

objects. The system provides

a graphical interface to the

operator by using freezeframe video capture technology, and places icons over the

video indicating where

suspected weapons may

reside on a person.

Using a single camera, the

technology displays and

tracks more than one person

at a time who might be

carrying concealed weapons,

greatly simplifying the

process of divesting suspicious objects. The product

does not interfere with any

medical device, including

pacemakers. The CWD can be

installed as a stand-alone

checkpoint screening tool or

as a fully integrated security

system encompassing multiple, networked CWD units

that can be controlled via

central station monitoring.

Images
INL TECHNOLOGIES

Dale K. Kotter

208-526-1954

Dale.Kotter@inl.gov

For more information

05-GA50220

Sensor Fusion Testbed

Experts agree that threat

detection can be improved

through the concurrent

analysis of multiple signatures, such as magnetics,

ultrasonic, acoustic, mm

wave, and infrared. The INL

CWD system can serve as a

platform to combine various

detection mythologies into a

single portal system. The

CWD is built on an open data

acquisition platform. The

portal configuration can be

tailored for specific applications and threats. INL welcomes partnering with other

institutions to further evaluate

novel weapon detection

configurations and technologies.

Field Evaluation

Capabilities

The INL has established field

evaluation capabilities at

Bannock County Courthouse

in Pocatello, Idaho. Three

CWD systems have been

networked together as part of

an integrated INL-designed

security system. Command

Enhancements allow detection and discrimination of small magnetic

field items such as composite metal guns

System

Specifications

• Accurately pinpoints

concealed weapons

• Reduces false alarms

• Passive non-contact

imaging

• No medical device

interference

• Reduce workload of

security personnel

• Video archiving

• Can be integrated

with CCTV, two-way

voice, door interlock,

cardkey access

systems and biometric

applications

Concealed Weapons Detection

System

and control functions for the

entire security system are

accomplished at a central

security center, where one

security guard can monitor

and communicate with the

entire security system using

audio, video, and computer

networks. The CWD system

also interfaces with an

automatic door locking

system to control egress if a

threat is detected.

Technology

Enhancements

We have demonstrated that

certain classes of weapons

and electronic items, such as

pagers and cell phones,

produce unique spectral

signatures that can be used for

automated identification and

classification. We use statistical analysis tools and a

variant of a probabilistic

neural net (PNN) to analyze

the spectrum generated when

a person passes through a

portal. The algorithms

perform a type of pattern

recognition and calculate a

probability factor that the

collected spectrum signature

correlates to a known database of weapon vs. nonweapon responses.

The CWD data acquisition

system performs a spatial

analysis (x-y-z axis) of the

magnetic spectra and computes the location of the threat

object. A graphic representation of threat location is

overlaid onto a live video

image of a person walking

through a sensor portal. The

ability to define threedimensional target signatures

greatly improves the predictive precision of the patternrecognition algorithm.

We have developed a variable

detection threshold method to

tailor the CWD to local

security conditions and to

dynamically adjust the

CWD’s threshold sensitivity

in order to decrease system

false alarm rates.

R&D Status

Personal items such as steel

shank shoes, under wire bras,

and cell phones, often generate false-positive alarms and

are routinely ignored as

nuisance events by conventional detectors. Terrorists

may attempt to exploit this

weakness in security screening. Research is in progress to

establish a database of

magnetic signatures that

represent common threat/nonthreat items. The INL has the

capability to develop and

implement intelligent magnetic spectra pattern classification algorithms to further

detect, classify and discriminate customer specific

screening requirements.