uwb short range (radar) sensorsuwb short range...

UWB Short Range (Radar) SensorsUWB Short Range (Radar) SensorsUWB Short Range (Radar) SensorsUWB Short Range (Radar) Sensors

Reiner S. Thomä

IlmenauUniversity of Technology

Slide 1Technische Universität Ilmenau FG Elektronische Meßtechnik

WCI 2008

UWB – An Idea Whose Time Has Come?UWB – An Idea Whose Time Has Come?

Communication – Localization – Sensors

Communication:• “New frequencies” for short range communication q g

FCC 2002: 3.1 - 10.6 GHzBack to Marconi?

• Coexistence with other systems • Simple systems and hardware

Localization:• Unprecedented delay resolution (bandwidth!) • Multipath resistance

Sensors:• Material penetration (low frequencies!)• More information on materials and shape of scanned media and bodies


2008

UWB Spectrum Regulation - FCC

-30

z]-40

m/M

Hz

critical gapfor sensor

applications

-60

-50

vel [

dBm

EIRP = -41,3 dBm/MHzR l f fi ld

0,5 mW- 3 dBm

-70

-60

RP

lev

indoor applications

Rms value of field strength of 500 µV/m measured GPS

band

-80

EI

hand held devices, outdoorpp

1 10

at 3 m distance and 1 MHz bandwidth

frequency [GHz]EIRP = effective isotropic radiated power


2008

Basic UWB System ConsiderationsBasic UWB System Considerations

• Impulse radio, OFDM or direct sequence spread spectrum?

• Integrated system design example – Experimental system as used for all examples given

• Basic localization principles • Radar imaging


2008

System Characterization in the Time Domain

Impulse excitation:

( ) ( ) ( ) ( )ttxthty δ~if~

Excitation: reaction IRFExcitation:Impulse

reaction ~ IRF

LTI-Systemh(t)h(t)x(t) y(t)


2008

Correlation Processing

Excitation: noise

reaction

(t)LTI-System

h(t)x(t)

y(t) l t

h(t)yy(t) correlator

cyx(τ)x

Cross-correlation ~ IRF


2008

Maximum Length Binary Sequence (MLBS)

S

Ideal 4th order M-Sequenceone period

ctNT =0V M

S

time

one chip tc = 1/fc

N = 2n-1Number of chips:Time-Bandwidth-Product: nTB 2≈Auto correlation function Time Bandwidth Product: TB 2≈

1

Auto correlation function

CorrelationCorrelationGain!10 lg(TB)


2008

0

Single Chip Demonstrator System in SiGeSingle Chip Demonstrator System in SiGe

RF-clock to DSPADCVee = 3 V

Rx

TTx Rx

ADCli l k

Courtesy M. Kmec,TU Ilmenau


2008 8to DSPSampling clockTrigger

Experimental System (Baseband)Experimental System (Baseband)

Transmit signal spectrum (not calibrated)

Direct wave

C t lkDirect wave

Cross-talkSystem impulse response Noise floor

IR, not calibrated IR calibrated


2008

35dB dynamic range 60dB dynamic range

Demonstrator System 3.5…10.5 GHzDemonstrator System 3.5…10.5 GHz

Digitalhift i t

Modulated MLBS

RF-clockshift register

to sensor

7 GHz

MLBS

Binarydivider

Complex ImpulseResponse Function

00 9001/2LO unit

Sampling Clock13.6 MHz

HDigital signalprocessingIRF ADC

T&H

from sensor

IF – Front - EndBase Band Processing


2008

Basic Radar Signal Processing Basic Radar Signal Processing

TxPort 1

Tx

reference

Targeta1

b2Rx

2

Port 2IRF h(t)

• Radar echo depends on target size shape and materialsize, shape, and material composition• desired target information: ( )t permittivity

gdistance, location, orientation, speed, shape, material

iti iti

( )τεε ,,,, tzyx=

( )τμμ ,,,, tzyx=

ε permittivityμ permeabilityσ conductivityx,y,z space coordinatest observation time


2008

composition, recognition… ( )τσσ ,,,, tzyx=t observation timeτ delay time

Spatial Processing and Radar Imaging Spatial Processing and Radar Imaging

Measured data

Focused data

Measured data

ObjectCross range single scan

contribution

Time delay Focused dataTime delay

Measured data


2008

UWB Localization and Sensor ApplicationsUWB Localization and Sensor Applications

•Localization of active devices (tags) •Localization and recognition of passive objectsLocalization and recognition of passive objects •Imaging of structures and environments•Material characterization

•Non destructive testing•Civil engineering and miningSh t i ti•Short range navigation

•Industrial sensing•Safety and security•Automotive •Biomedical engineering•Law enforcement, military, y•Search and rescue


2008

Humanitarian Demining (GPR)

3 x 3 UWB array and metal detector

9 channel M-Sequence UWB Radar

Courtesy QinetiQ

Courtesy MEODAT and QinetiQ


2008

Humanitarian Demining (GPR)

APL and UXO Detection

“Wave penetration” into the soil

APL

R2M2 -Mine

APL3

cm

Courtesy Vrije Universiteit Brussels

Ground surface profile gained by the radar

(Demonstrating video)


2008

gained by the radar

Non-Destructive Testing in Civil Engineering

Experimental Set-up

Arrangement of 5 by 3 bricks


2008

Non-Destructive Testing in Civil Engineering

Detection of wall structures, artefacts, moisture

antenna polarisation

yyall bricks are dry

y

xx

y

the central brick was exposed to watery


2008

xx

Radar Sewer Tube CrawlerRadar Sewer Tube Crawler

Antenna unit

• radar unit• operation controlp• angle sensor• data interface

Test field in preparation with foreign objects


2008

g j

Radar Sewer Tube Crawler: Measurement exampleRadar Sewer Tube Crawler: Measurement example


2008

Detection of human body activities: cardiac & respiratoryDetection of human body activities: cardiac & respiratory

heart beat rate: 83

Measurement data withMeasurement data with background subtraction breathing stop breathing


2008

MRI Image EnhancementMRI Image Enhancement

Tracking of heart and lunge movement


2008

Cancer DetectionCancer Detection

Variation of water content Variation of water content b hi hb hi h

In vitro measurement of a human lung during by approaching the cancerby approaching the cancer

8888

a human lung during NaCl-Perfusion

8282848486868888

onte

nt [%

]on

tent

[%]

787880808282

Wat

wer

co

Wat

wer

co

7676


2008

Active Location ApproachActive Location Approach

Measured Example • cm (sub-cm) precision

2

2.5

t l t k

measured trackdetected wave front

circular wave front

R l t

1.5

tion

[m] actual track

time [ns]

Real antenna

?0.5

1

Y di

rect ϕ = 90°

45°

?

1 0 5 0 0 5 1

0

ϕ = - 45°

ϕ = 0°

ϕ = 45°

-1 -0.5 0 0.5 1

X direction [m]receive array

moved transmit antenna


2008 23

(Vivaldi antennas)transmit antenna

(bi-cone)

Active Location ApproachActive Location ApproachMeasured example: 3D-positioning

sandbox

Demonstrating video

Vivaldi-Array


2008

Passive ApproachPassive ApproachExample

2

2.5moving target(box 0,5 x 0,1 x 0,5 m)

1.5

2tio

n [m

]

0 5

1

Y di

rect actual track

measured track

0

0.5 measured track

-1 -0.5 0 0.5 1

X direction [m] receive array(Vivaldi antennas)

transmit antenna(bi cone)


2008 25

(Vivaldi antennas)(bi-cone)

Search and Rescue Applications Search and Rescue Applications

Detection of people buried by an avalanche

Detection of people buried by earthquake

Tracking of peoplebehind the wall

Rescue personnel, injured persons in static environments

Recognition of building structures• hidden rooms and cavities

• detection respiratory activity• detection cardiac activity• moving persons

• wall structures• blocked entrance


2008

g

Tx/Rx node

y[m] [x3,y3]

Tx node

[0,0]

[xm100,ym100] Rx node

[ , ]

[xm1,ym1]

[x2,0]

x[m]


2008

Imaging of Environments: Measured ExampleImaging of Environments: Measured Example

• Rx1 and Rx 2: anchor nodes

• Tx: roaming illuminator node

• Direct and scattered wave separated

• Tx position track estimated from direct wave

• Image of environment calculated from scattered waveImage of environment calculated from scattered wave

Measurement environment

Container

Measurement environment

Data measured by anchor node

Rx1

Direct wave

Rx1 Rx2

Tx moving

Engine 2

Engine 1 Wall Multipath components


2008

Imaging of Environments: Measured ExampleImaging of Environments: Measured Example

Engine 2Rx1 contribution to the focused image

Container

Rx1

Tx

the focused image - single snapshot

Engine 1Focused image from Rx1 and Rx2 contribution

Container Estimated track of

Rx1 Rx2

Tx moving

Engine 2 the Tx movement

Engine 1 Wall


2008

g

Imaging by “Bat-type” Sensors Imaging by “Bat-type” Sensors

2T

xR

x2R

x1

„Bat-type“ sensors are equipped with one Tx and two Rx antennas

Object 1

Object 2

R

No coherent cooperation of distributed sensors required

Sensor positioning maybe self j p g ycontained

Additional positioning (inertial sensors or by anchor nodes) may help

Tx Rx2Rx1Resulting image

y ) y p

Correlation of single snapshots

Object 1Object 2

snapshots


2008

Object 2

Imaging of Objects: ResolutionImaging of Objects: Resolution


200824

Localizing of people – through the wallLocalizing of people – through the wall

1st part of

Measurement scenario

500cm

1st part of the track

2nd part of the track

500cm

Table

3rd part of the track

4th part of Table the track

Test object

30cmWooden door

Furniture


2008

Rx1 Tx1 Rx2 Tx2 Rx3 Tx3200cm 200cm

Localizing of people – through the wallLocalizing of people – through the wall

Antenna arrangement

Demonstrating video


2008

Measurement scenario in reality

Through Wall Detection of Breathing ActivityThrough Wall Detection of Breathing Activity

Tx antenna Rx antennaTx antenna Rx antenna

40cm

Wooden door

200cm

5 times deep breath

Brick wall

5 times deep breath slow

5 times deep breath fast4 times flat breathing

Test object


2008

Test object

Detection of buried people

Detection of Breathing and heart beatDetection of Breathing and heart beat

e, n

s 20

22e, n

s 20

22e, n

s 20

22

Radar data after removing static scatterer

gatio

n Ti

me 22

24

26

gatio

n Ti

me 22

24

26

gatio

n Ti

me 22

24

26

Prop

ag 28

30

32

Backscattered signal modulated by rhythmic variations of the breast due to breathingPr

opag 28

30

32

Prop

ag 28

30

32

Backscattered signal modulated by rhythmic variations of the breast due to breathing

Breathing personBreathing personBreathing personBreathing person

Observation Time, s110 120 130 140

32


32


32

on T

ime

[ns] 10

20

on T

ime

[ns] 10

20

Prop

agat

io 30

40Prop

agat

io 30

40Radar data after enhancement of breathing activity


2008 35Breathing rate [Hz]

0.2 0.4 0.6 0.8 1 1.2

50

Breathing rate [Hz]0.2 0.4 0.6 0.8 1 1.2

50 of breathing activity

Through-Wall MeasurementsThrough-Wall Measurements

Light concrete ll

Wooden wall

wall

Bricks TimberBricks Timber

Hand held

TilTile

Hand held device

Tile

FloorSlide 36

Technische Universität Ilmenau FG Elektronische Meßtechnik

2008

Floor

Courtesy RADIOTECT project

Larvae detectionLarvae detection

Hylotrupes bajulusMeasurement set-up

Bi-static radar

Wood with larvaWood with larva


2008

Larvae detectionLarvae detection

Radargram after Background removal

ns] 16

Radargram after Background removal

ROI (region of interest)

rip ti

me

[n 182022

Movement of the larva( g )

OI

roun

d tr

2426

Movement of the operator (far away from the test object)

0 6

0.8

1

rgy

of R

O

observation time [s]0 20 40 60 80 100 120 140 160 180

0.2

0.4

0.6

lised

ene

r

0 20 40 60 80 100 120 140 160 1800

observation time [s]norm

al


2008 38

ConclusionsConclusions

• UWB sensor application offers clear advantage over other radar, optical and ultrasound sensors.

• Frequency regulation not optimal for sensor li tiapplication.

• Low power, high clock rate integrated circuit technolog req ired (SiGe)technology required (SiGe).

• Huge absolute and relative bandwidth requires paradigm shifts from narrowband to widebandparadigm shifts from narrowband to wideband principles.

• Sensor cooperation and spatial distributedSensor cooperation and spatial distributed processing (sensor networks).


2008

AcknowledgementAcknowledgement

Contributions by Dr. Sachs, Dr. Zetik, Dr. Hirsch, Dr. Helbig

Ultra-Wideband Radio Technologies for gCommunications, Localization and Sensor Applications


2008

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