Overview of New Surveillance Technologies

Stanley E. BorekAir Force Research Laboratory

Information DirectorateStanley.Borek@rl.af.mil

Overview of New Surveillance

Technologies• Background• Concealed Weapons Detection (CWD)/Concealed Explosives Detection

(CED) Technologies–Terahertz Imaging System For CWD– Identification of Concealed Explosives via THZ Absorption

Spectroscopy Using Principal Component Analysis– Electromagnetic CWD at a Distance– Non-Linear Acoustic CWD– Detecting Concealed Weapons at a Safe Distance Using

Active Millimeter Wave Radar– Detection and Classification of Concealed Items via Magnetic

Signature Analysis– Focal Plane Array-Based Millimeter Wave Imaging Radiometer– Imaging with Millimeter Wave Focal Plane Arrays

• Through the Wall Surveillance (TWS) Technologies– Random Array TWS Imaging via Bistatic Radar Technology– Low-Cost Radar Sensors for Locating and Tracking

Individuals within Buildings• Summary

Overview of New Surveillance

Technologies• Background

– AFRL/IF under sponsorship of the Department of Justice’s (DOJ),National Institute of Justice (NIJ) Office of Science and Technology (OS&T) currently developing and evaluating advanced CWD and TWStechnologies • Two categories:

– Inexpensive, handheld systems for CWD and TWS– Fixed or mounted immoveable systems (e.g. portals) for CWD– Portable, personal computer (PC) based standoff systems to enable

the determination of events during critical incident situations for TWS • Objectives:

– locating hidden weapons on an individual’s torso (CWD)– locating an individual(s) behind a wall or door (TWS)

– AFRL/IF is supporting the Department of Homeland Security (DHS) on CWD research efforts via the Homeland Security Advanced Research Projects Agency (HSARPA)

– Relationship is closely coordinated technical effort through AFRL

Overview of New Surveillance

Technologies

Concealed Weapons Detection (CWD)/Concealed Explosives Detection

(CED) Technologies

Overview of New Surveillance

TechnologiesTerahertz Imaging System for Concealed Weapon Detection

HSARPA Phase I SBIR Contract - Spire Corporation

Program objectives:

• Measure terahertz atmospherictransmission

• Define portable standoff imagingsystem

• Design proof-of-concept system• Estimate system performance

Technical approach:

• Use terahertz FTIR interferometer • Heterodyne detection required formaximum sensitivity

• Stationary transmitter antenna, andrastered receiver antenna

• Clothing loss assumed at 10-20 dB, 10 dB receiver noise figure

Overview of New Surveillance

TechnologiesTerahertz Standoff Imager Design with Heterodyne Detection

Using Quantum Cascade Lasers – Spire Corporation

Illustration of a terahertz standoff imaging system at 50 m target distance.

Overview of New Surveillance

Technologies

Identification of Concealed Explosives via THz AbsorptionSpectroscopy Using Principal Component Analysis

HSARPA Phase I SBIR Contract – Intelligent Optical Systems & RPITHz Spectroscopy for Standoff Detection of Explosives and Weapons• THz radiation is safe to humans• Frequency dependence of absorbed or reflected THz radiation isindicative of explosives and other dielectric materials

– Stand off spectroscopic analyzer• Efficient reflection over broad wavelength regions is indicative ofmetals and ceramics

– Potential weapons detection• THz radiation is minimally absorbed by paper, leather, plastic,cardboard, clothing

• THz radiation can be transmitted through the atmosphere within a window of 0.1 to 3 THz, with the exception of numerous water absorption lines

Overview of New Surveillance

TechnologiesAPPROACH TAKEN TO SHOW FEASIBILITY OF IDENTIFICATION AND

DETECTION - Intelligent Optical Systems & RPI• Obtained absorbance spectra via both transmissionand reflection

– Four explosives: TNT, RDX, HMX, PETN– Four non-explosives: sugar ,flour, soap, salt– Four coverings: paper, polyethylene sheet, cotton cloth, and

leather• Selected signature wavelengths (reduced dimensions of data sets)• Applied principal components analysis (PCA)

– Reduce dimensionality of data by selection of signaturewavelengths

– Assemble table of absorbances (ABS) (from diffusereflectance) vs. signature wave number for each explosivecompound

– PCA allows one to calculate ABS along N new coordinatesthat are orthogonal and that are linear combinations of theoriginal coordinates in order to group similar compoundsinto closer clusters

Overview of New Surveillance

TechnologiesBasic THz Standoff Detection Concept - Intelligent Optical Systems & RPI

Detection is Ultimate Objective

http://www.bearspage.info/h/tra/ca/bc/va/i/se/s90.jpg

2-Axis Scanning THz Laser(Sequential Monochrome Scanner) Vi

deo

Cam

era

THz DetectorTHz Detector

THz Beam Path

Field of View

Raster SweepReflected Wavefronts

Potential Threat

Perceived threat.

http://www.bearspage.info/h/tra/ca/bc/va/i/se/s90.jpg

False color imaging would be used to identify the threat and to classify as to explosive, metal weapon, ceramic, etc

Overview of New Surveillance

TechnologiesElectromagnetic Concealed Weapons Detection at a Distance

HSARPA Phase I SBIR Contract - Pharad

• Electromagnetic (EM) spectral analysis approach • Wideband millimeter-wave signals used to excite naturalresonances on a concealed weapon

• Measurement of resonances across entire Ka-band (26 – 40 GHz) – Create mm-wave EM ‘signature’ or ‘fingerprint’ of target with

unique features• Wideband mm-wave EM signature identifies object from database oftargets

• Resolution: 2 – 3 mm with ± 1 dB RF power measurement accuracy

Features

Overview of New Surveillance

TechnologiesElectromagnetic Concealed Weapons Detection at a Distance

Wideband Electromagnetic Millimeter-Wave(Ka-band) Sensors

Interrogation Zones

Central Processing

Concept - Pharad

Overview of New Surveillance

Technologies

Non-Linear Acoustic Concealed Weapons Detection (CWD)NIJ & HSARPA Phase I SBIR Contracts – Luna Innovations

ADVANTAGES

• Audio sound penetrates clothing andcan be safe

• Ultrasonics is like a laser and highlydirectional

• Weapons behave differently thantissue and have resonances that canbe detected

CHALLENGES

• Acoustics spread too quickly• Ultrasonics has trouble with thickclothing since it is highly attenuating

• Advanced processing techniques areneeded to classify sample signaturesto distinguish weapons

– Existing methods cannot bring advanced signal processing to full advantage

Overview of New Surveillance

Technologies

Beam-mixing makes acoustics a viable option for CWD – Luna Innovations

NAC

f1

f2

f1-f21. Locate2. Penetrate

3. Detect

• Luna’s nonlinear acoustics (NAC)overcomes the penetration/resolutiontradeoffs of traditional acoustics.

• Acoustics is:– Cost competitive– Sensitive to metals and non-metals– Safe and does not raise privacy

concerns

Overview of New Surveillance

TechnologiesDetecting Concealed Weapons at a Safe Distance

Using Active Millimeter Wave Radar

NIJ BAA & HSARPA SBIR Phase I Contracts - Personnel Protection Technologies, Inc.

• Off the shelf collision avoidance radar (77 GHz)• Transmit both horizontal and vertical polarization• Three modes of operation:

– Radar detection, threat evaluation, and handoff to camera– Computer vision based detection for handoff to radar– Man-in-the-loop interaction with the camera to identify targets

• Algorithms will be developed to process the polarization maps that encompass the target, for the purpose of identification

Overview of New Surveillance

Technologies

System Concept – Personnel Protection Technologies, Inc.

Overview of New Surveillance

TechnologiesDetection and Classification of Concealed Items via Magnetic

Signature Analysis NIJ Funded BEA - Idaho National Laboratory

• Under NIJ sponsorship INL has developedan array of magneto-resistive gradiometersensors configured into a walk-throughweapons detection portal

Baseline Technology• Responds to ferromagnetic materials• Accurately pinpoints the number, locationand size of weapons

• Uses freeze-frame video capture technologyto document events

• Further developed to discriminate andclassify type of threat

Commercialized by View Systems,Inc. as Secure Scan 2000

Overview of New Surveillance

TechnologiesTechnology Enhancements to CWD System – Idaho National Laboratory

• Classes of weapons and electronic itemsproduce unique magnetic signatures

• Advanced signal processing is beingdeveloped to discriminate and classifythreat and non-threat items

• Intelligence will be added to automaticallyscreen common non-threat items such asPDAs, cell phones, underwire bras, andshoes containing steel shanks

• Enhancements allow detection anddiscrimination of small magnetic field items

• Can detect and classify a combination ofthreats when items are sufficientlyspatially separated

Overview of New Surveillance

TechnologiesFocal Plane Array-Based Millimeter Wave Imaging

Radiometer NIJ Funded Contract - Lockheed Martin

• Passive detection and measurement of electromagneticradiation at Millimeter wavelengths

• Measures contrast between surrounding environment and areaundergoing scan

– Aperture size achieves necessary resolution and stand-off• Penetrates opaque materials, such as clothing• Utilizes rudimentary Automatic Target Recognition (ATR) Algorithms• Brassboard system capable of real time operation with stand-offdetection at ~4.6 meters (15 feet)

Overview of New Surveillance

TechnologiesProof-of-Concept & Commercial Systems – Lockheed Martin

Brassboard System Brijot/Lockheed MartinSystem

Overview of New Surveillance

TechnologiesImaging with Millimeter Wave Focal Plane Arrays

NIJ Funded Contract – Raytheon Vision Systems/UCLA

Bolometer Based MMW Imager Physics

PMMWI - Released VOX Bolometer

Pixel and MicroAntennaAntenna Captures mmw Radiation

Energy Coupled to BolometerNitride Legs for Thermal Isolation

mmw Power Flows from Antenna through Bridge

Square Bolometer Bridge

Bowtie Shaped Bridge

C Connections toReadout Circuitry

Overview of New Surveillance

Technologies

Through the Wall Surveillance (TWS) Technologies

Overview of New Surveillance

TechnologiesRandom Array TWS Imaging via Bistatic Radar Technology

NIJ Funded Contract – Akela, Inc.

DISTRIBUTEDIMAGINGNETWORKCONCEPT

• Individuals and vehicles become sensor nodes• Random array improves imaging by reducing ghosts• Wireless network receives data and distributes information• View of operational space changes as sensors move• Modular approach allows operational flexibility• Network centric sensor

Overview of New Surveillance

TechnologiesDISTRIBUTED IMAGING NETWORK CURRENT ARCHITECTURE – AKELA, INC.

• Completely wireless system is program goal

Overview of New Surveillance

TechnologiesLow-Cost Radar Sensors for Locating and

Tracking Individuals within BuildingsNIJ Award – University of Texas at Austin

Proposed: A sensor concept combining Doppler and Direction-Of-Arrival(DDOA) information to track multiple movers through walls

Objectives: (1) Develop low-cost radar sensor concepts for personneldetection based on commercial wireless products(2) Collect an extensive database using the developed sensorsand to exploit the data for personnel location, tracking, and ID

Unique Features: (1) Use of Doppler features from human movements tosuppress stationary clutter such as buildings and walls(2) Use very few receiver elements to obtain DOA trackingof multiple human targets(3) Use of Mass-market wireless products for very low cost sensor development

Anticipated (1) Novel sensor design and demonstrationResults: (2) Database of human radar signatures & radar

features of human movements knowledge base

Overview of New Surveillance

Technologies

• Summary

– DOJ/NIJ and DHS have combined resources to actively develop solutions to the tough challenges facing technology applications to state-of-the-art systems for CWD, CED, and TWS

– Research & Development efforts range from practical technical applications of acoustic, radar, and terahertz frequencies

– Seven technology applications for CWD presented; one for CED, two for TWS– Research results in the area of technology applications of Terahertz frequencies for CWD and CED has been positive

– Millimeter Wave Imaging Technologies show promise for accomplishing reasonable stand-off operation for CWD

– Nonlinear Acoustic Technology shows promise for accomplishing CWD via innovative application of frequency scanning and resonance principles

– Bistatic Radar Technology is a novel approach for dynamically accomplishing 3D imaging for TWS

– AFRL/IF is working closely with DOJ/NIJ and DHS to develop, mature, and place these technologies in the field as viable systems