Precision Indoor Personnel Location and Tracking for Emergency RespondersTechnology Workshop, August 6-7 2007

Worcester Polytechnic Institute, Worcester, MA

Positioning of incident responders- scenarios, user requirements and enablers

Positioning of incident responders- scenarios, user requirements and enablers

Jouni RantakokkoSwedish Defence Research Agency

Jouni RantakokkoSwedish Defence Research Agency

This work was funded by the− Swedish Governmental Agency for Innovation Systems− Swedish Emergency Management Agency − Swedish Defence Materiel Administration

Participating organizationsParticipating organizations

Technical expertsSwedish Defence Research Agency, FOIRoyal Institute of Technology, KTHLuleå University of Technology, LTUSAAB AerotechSAAB Bofors Dynamics ABSwedish Defence Materiel Administration, FMV

User representativesSwedish Rescue Services AgencyRescue Service in LinköpingNational Criminal PoliceArmy Combat School

Technical expertsSwedish Defence Research Agency, FOIRoyal Institute of Technology, KTHLuleå University of Technology, LTUSAAB AerotechSAAB Bofors Dynamics ABSwedish Defence Materiel Administration, FMV

User representativesSwedish Rescue Services AgencyRescue Service in LinköpingNational Criminal PoliceArmy Combat School

Scenarios, user needs and requirementsScenarios, user needs and requirements

ScenariosMilitary personnel, peace-keeping or peace-enforcement

Search through building for sniper

Navigation through mine field

PoliceHostage situation in large building

Under-cover surveillance of suspects entering building (e.g. shopping mall or night club)

Search for fugitives in rural areas

FirefighterFire in multi-story apartment building

Fire in complex building (shopping mall, night club, office buildings)

Military personnel, peace-keeping or peace-enforcement

Search through building for sniper

Navigation through mine field

PoliceHostage situation in large building

Under-cover surveillance of suspects entering building (e.g. shopping mall or night club)

Search for fugitives in rural areas

FirefighterFire in multi-story apartment building

Fire in complex building (shopping mall, night club, office buildings)

User needs and requirementsUser needs and requirements were mainly discussed

from the stand-point of current tactical behaviorLikely that a personnel positioning system enable improved

tactical behavior, which in turn will yield new requirements

Development of improved tactical behavior requires extensive experimentation and training with positioning systems

Tactical behavior different in US and Sweden – does this affect the identified requirements?

User needs and requirements were mainly discussed from the stand-point of current tactical behavior

Likely that a personnel positioning system enable improved tactical behavior, which in turn will yield new requirements

Development of improved tactical behavior requires extensive experimentation and training with positioning systems

Tactical behavior different in US and Sweden – does this affect the identified requirements?

User needs and requirementsSimilar needs and requirements for police, military and

firefightersMore dependant on the scenario environment

Benefits with a personnel positioning system increases as the building size/complexity increases

Easier to obtain situational awareness in smaller buildings

Example - firefightersstated limited need for positioning system in typical apartment fires

focus was on large buildings and unpredicted events where typical tactical behavior insufficient

US events (9/11 and Charleston) shows importance of tracking firefighters under collapsed buildings?

Similar needs and requirements for police, military and firefighters

More dependant on the scenario environment

Benefits with a personnel positioning system increases as the building size/complexity increases

Easier to obtain situational awareness in smaller buildings

Example - firefightersstated limited need for positioning system in typical apartment fires

focus was on large buildings and unpredicted events where typical tactical behavior insufficient

US events (9/11 and Charleston) shows importance of tracking firefighters under collapsed buildings?

Examples of identified user needsEfficient local command and control M, P, F

Rescue of injured personnel M, P, F

Navigation through complex buildings M, P, F

Safe exit (e.g. from collapsing building) F

Friendly-fire / Blue-force-tracking M, (P)

Distance and heading to targets/threats M, P

Health status and automatic alarm functionality M, P, F

Know what rooms have been ”cleared” (searched) M, P, (F)

After-action review (de-briefing) and training analysis M, F, (P)

Safe navigation through e.g. mine fields M

Fugitive movement pattern analysis (positions of dogs) P

Free the radio resource for command and control M, P, F

Efficient local command and control M, P, F

Rescue of injured personnel M, P, F

Navigation through complex buildings M, P, F

Safe exit (e.g. from collapsing building) F

Friendly-fire / Blue-force-tracking M, (P)

Distance and heading to targets/threats M, P

Health status and automatic alarm functionality M, P, F

Know what rooms have been ”cleared” (searched) M, P, (F)

After-action review (de-briefing) and training analysis M, F, (P)

Safe navigation through e.g. mine fields M

Fugitive movement pattern analysis (positions of dogs) P

Free the radio resource for command and control M, P, F

What needs to be estimated?Position (x,y)

Height

Position error (and integrity monitoring)

Heading for weapon and/or body

Distance and direction to targets and threats

Who needs the estimated positions?Local command

Other units in group

What needs to be estimated?Position (x,y)

Height

Position error (and integrity monitoring)

Heading for weapon and/or body

Distance and direction to targets and threats

Who needs the estimated positions?Local command

Other units in group

Examples of user requirementsy

xz

y

xz

Examples of user requirements

Preliminary requirements listAccuracy (x-y): < 1 meter in all environments (what room?)

Accuracy (z): < 2 meter (what floor?)

100 % availability

Accuracy in estimated heading?

Weigth < 1 kg

Battery – minimum 8 hours, several days desired

Robustness more important than stealth

Encrypted data transfer

Combine positioning information with health status

Preliminary requirements listAccuracy (x-y): < 1 meter in all environments (what room?)

Accuracy (z): < 2 meter (what floor?)

100 % availability

Accuracy in estimated heading?

Weigth < 1 kg

Battery – minimum 8 hours, several days desired

Robustness more important than stealth

Encrypted data transfer

Combine positioning information with health status

Examples of user requirements

No dependence of pre-installed infrastructure

Integrated positioning and communication system

Covert positioning system

Modular system

Avoid large antennas, integrate antenna/cables into uniform

No dependence of pre-installed infrastructure

Integrated positioning and communication system

Covert positioning system

Modular system

Avoid large antennas, integrate antenna/cables into uniform

Different users Different users -- different systemsdifferent systems

”Safety-of-Life” critical systemsSpecial forces, local/state/federal ”SWAT-teams”, firefighters

Accuracy and availability before cost

Increased safetySoldiers, police, correction officers, security guards

Availability, accuracy and cost important

Demanding consumers/applications (and ”first adopters”)Alarm functionality (hospitals - social workers - immigration), interactive

services, gaming, surveillance of visitors in companies, …

Availability and cost important, errors accepted

Regular consumers (mass market)Positioning of emergency calls, games, interactive services, …

Cost most important (e.g. when integrating pos/nav in all mobile phones)

”Safety-of-Life” critical systemsSpecial forces, local/state/federal ”SWAT-teams”, firefighters

Accuracy and availability before cost

Increased safetySoldiers, police, correction officers, security guards

Availability, accuracy and cost important

Demanding consumers/applications (and ”first adopters”)Alarm functionality (hospitals - social workers - immigration), interactive

services, gaming, surveillance of visitors in companies, …

Availability and cost important, errors accepted

Regular consumers (mass market)Positioning of emergency calls, games, interactive services, …

Cost most important (e.g. when integrating pos/nav in all mobile phones)

Possible tradePossible trade--offs offs -- performance vs costperformance vs cost

Potential users Predicted needs Maximum cost

Special forces,local/state/federal ”SWAT-teams”, firefighters

100 % availability and sub-meter accuracy, robust against interference/jamming, integrity monitoring and position error estimates

US$ 1.000 - 10.000

Soldiers, police, correction officers, security guards (at sensitive objects)

100 % availability, lower accuracy and robustness demands, integrity monitoring

US$ 100 - 1.000

Demanding applications/consumers Good accuracy during normal conditions, high availability desired but position errors accepted occasionally, integrity monitoring

US$ 10 - 100

Mass market Good accuracy during normal conditions, acceptans for large errors and loss of servicein certain conditions (e.g. indoors, tunnels)

US$ 1 – 10

EnablersEnablers

”Draft” report available in the report data base at www.ee.kth.se

“Positioning of emergency personnel in rescue operations -possibilities and vulnerabilities with existing techniques and identification of needs for future R&D”, Technical report TRITA-EE 2007:037, Royal Institute of Technology, Stockholm, Sweden

Part of the command and control systemPart of the command and control system

The positioning system must includeEstimation of positions, heading, health statusTransfer of information (local command, other units)Presentation of informationDecision support (navigation, safe exit, etc)

The positioning system must includeEstimation of positions, heading, health statusTransfer of information (local command, other units)Presentation of informationDecision support (navigation, safe exit, etc) WPI: Precision Personnel

Locator (PPL) System

DARPANICE

Summary of existing positioning techniquesSummary of existing positioning techniques

GNSSExiting future with GPS, Galileo, GLONASS and Beidou/COMPASS(?), new receiver algorithms with increased sensitivity (assisted-receivers,high-sensitivity receivers), EGNOS, pseudolites

Substantially improved availability expected indoors, poor accuracy still

Insufficient performance indoors due to signal attenuation and multipath propagation, sensitive against interference and jamming

Performance with future combined receivers (GPS+GALILEO => 50 satellites)?

GNSSExiting future with GPS, Galileo, GLONASS and Beidou/COMPASS(?), new receiver algorithms with increased sensitivity (assisted-receivers,high-sensitivity receivers), EGNOS, pseudolites

Substantially improved availability expected indoors, poor accuracy still

Insufficient performance indoors due to signal attenuation and multipath propagation, sensitive against interference and jamming

Performance with future combined receivers (GPS+GALILEO => 50 satellites)?

Summary of existing positioning techniquesSummary of existing positioning techniques

Local radio-based indoor positioningPre-installed: RFID, UWB, ZigBee (IEEE802.15.4), WLAN, Bluetooth, ...

Ranging-based systems utilizing bring-your-own infrastructureE.g. TDOA/TOA systems, vast power advantage compared to GNSS

Mobile ad-hoc networks with node-ranging and distributed positioningFor very harsh environments, mobility and geometry restricts performance

Signals-of-opportunity (SOP)

Expect insufficient indoor performance in large buildings due tomultipath propagation, frequency regulations limits possibilities

Indoor performance of proposed ”Governmental” UWB and likelihood for acceptance from FCC? What performance can be achieved with radio-based systems (”pseudolites”) at lower frequencies (200-500 MHz) with limited bandwidths (100 MHz)? What can SOP give us?

Local radio-based indoor positioningPre-installed: RFID, UWB, ZigBee (IEEE802.15.4), WLAN, Bluetooth, ...

Ranging-based systems utilizing bring-your-own infrastructureE.g. TDOA/TOA systems, vast power advantage compared to GNSS

Mobile ad-hoc networks with node-ranging and distributed positioningFor very harsh environments, mobility and geometry restricts performance

Signals-of-opportunity (SOP)

Expect insufficient indoor performance in large buildings due tomultipath propagation, frequency regulations limits possibilities

Indoor performance of proposed ”Governmental” UWB and likelihood for acceptance from FCC? What performance can be achieved with radio-based systems (”pseudolites”) at lower frequencies (200-500 MHz) with limited bandwidths (100 MHz)? What can SOP give us?

Summary of existing positioning techniquesSummary of existing positioning techniques

Inertial navigation sensors and systemsRobust positioning

Development of MEMS-sensors allows for very small, light-weight, low-powered, and inexpensive(?) sensors - suitable for first responders

Error increases with time, heavily dependant on how object moves

What performance, and robustness against movement patterns, can be achieved with foot-mounted sensors?

Inertial navigation sensors and systemsRobust positioning

Development of MEMS-sensors allows for very small, light-weight, low-powered, and inexpensive(?) sensors - suitable for first responders

Error increases with time, heavily dependant on how object moves

What performance, and robustness against movement patterns, can be achieved with foot-mounted sensors?

GNSS

DR

AHRSFilter

Pedometer

IMURight foot

IMULeft foot

BAROMETER

Height-Filter

GNSS/DRFilter

Atm press

Vertical acc.

GNSS height Map

Position

Position error

HeightHeight error

Heading/Attitude

GNSS Position

Compass misalignment

Map height

3 acc

3 magn

3 gyro

Heading/Attitude error

IMU

Sensor fusion is neededSensor fusion is neededExample: decentralized sensor fusionExample: decentralized sensor fusion

Example: integration issuesExample: integration issues

Boots- IMU / AHRS

(attitude and heading reference system)

Helmet - GNSS antenna- Radio antenna- Compass

Arm/Body/Weapon/Helmet ?- Display- Controller

Body / torso ?- GNSS receiver- Radio- Compass / AHRS- Pedometer- Barometer- Battery- ”Computer”

SummarySummary

Affordable, robust and accurate personnel positioning system keytechnology to improve safety of military, police, firefighters

Efficient local command and control

Todays technology insufficient – crucial user requirements cannot be fulfilled (simultaneously)

3D positioning accuracy and availability indoorsIntegrity monitoring, estimate of position errorsPrice, size, weight, batteryTactical behavior

Sensor fusion approach needed to meet user requirementsWhat sensors should be used?How should the sensor data be combined?

Affordable, robust and accurate personnel positioning system keytechnology to improve safety of military, police, firefighters

Efficient local command and control

Todays technology insufficient – crucial user requirements cannot be fulfilled (simultaneously)

3D positioning accuracy and availability indoorsIntegrity monitoring, estimate of position errorsPrice, size, weight, batteryTactical behavior

Sensor fusion approach needed to meet user requirementsWhat sensors should be used?How should the sensor data be combined?

Initial results from TDOA-based positioning measurements

Initial results from TDOA-based positioning measurements

Example: TDOA positioningExample: TDOA positioningTDOA/TOA-based systems, portable infrastructure

ExampleSimple wideband radio transmitters placed on soldiers

>3 wideband digital receivers positioned around building

Receivers estimate their own positions and (possibly) perform time synchronization

Received sampled data transmitted to central unit (e.g. C2 vehicle)

Differences in traveled time to receivers are estimated (correlation)

Differences in travel distance calculated from TDOA-estimates

Transmitter positions - intersection between hyperbolic curves

All estimated unit positions distributed through radio to all units inside building

TDOA/TOA-based systems, portable infrastructureExample

Simple wideband radio transmitters placed on soldiers

>3 wideband digital receivers positioned around building

Receivers estimate their own positions and (possibly) perform time synchronization

Received sampled data transmitted to central unit (e.g. C2 vehicle)

Differences in traveled time to receivers are estimated (correlation)

Differences in travel distance calculated from TDOA-estimates

Transmitter positions - intersection between hyperbolic curves

All estimated unit positions distributed through radio to all units inside building

Example: TDOA positioningExample: TDOA positioning

Estimation of TDOA in receiver through correlationCRLB - Cramer-Raó Lower Bound

Lowest possible variance for an unbiased estimator in AWGN

Can we achieve the CRLB?Synchronization errors (time and frequency)

Multipath

Interference

Estimation of TDOA in receiver through correlationCRLB - Cramer-Raó Lower Bound

Lowest possible variance for an unbiased estimator in AWGN

Can we achieve the CRLB?Synchronization errors (time and frequency)

Multipath

Interference

232

2116

3)(SNR

SNRTW

CRLB t+

=∆π

T – observation intervalW – bandwidthSNR – signal-to-noise-ratio

Example: TDOA positioningExample: TDOA positioning

Factors that will affect performanceTransmitters

Bandwidth, transmit power, waveform

ReceiversNumber of receivers, geometry, time and frequency synch.

BuildingMultipath, signal attenuation

Factors that will affect performanceTransmitters

Bandwidth, transmit power, waveform

ReceiversNumber of receivers, geometry, time and frequency synch.

BuildingMultipath, signal attenuation

Example: TDOA positioningExample: TDOA positioning

Measurement set-upThree wideband receivers (8.5 MHz) placed outside 1st floor concrete/stone – 2nd floor wood – metal roofTransmitter inside building (178, 306 and 1125 MHz)Time synchronization error up to 20 ns20 ms data collection

Measurement set-upThree wideband receivers (8.5 MHz) placed outside 1st floor concrete/stone – 2nd floor wood – metal roofTransmitter inside building (178, 306 and 1125 MHz)Time synchronization error up to 20 ns20 ms data collection

-150 -100 -50 0 50-60

-40

-20

0

20

40

60

80

100

120

140

x-koordinat

y-ko

ordi

nat

HUS

Pejl 2

Pejl 1

Pejl 3

Example: TDOA positioningExample: TDOA positioning

-150 -100 -50 0 50-60

-40

-20

0

20

40

60

80

100

120

140

Position 1

178 MHz306 MHz

1125 MHz1st floor

Example: TDOA positioningExample: TDOA positioning

-150 -100 -50 0 50-60

-40

-20

0

20

40

60

80

100

120

140

Position 2

178 MHz306 MHz

1125 MHz1st floor

Example: TDOA positioningExample: TDOA positioning

-150 -100 -50 0 50-60

-40

-20

0

20

40

60

80

100

120

140

Position 3

178 MHz306 MHz

1125 MHz1st floor

Example: TDOA positioningExample: TDOA positioning

-150 -100 -50 0 50-60

-40

-20

0

20

40

60

80

100

120

140

Position 4

178 MHz306 MHz

1125 MHz2nd floor

Example: TDOA positioningExample: TDOA positioning

-150 -100 -50 0 50-60

-40

-20

0

20

40

60

80

100

120

140

Position 5

178 MHz306 MHz

1125 MHz2nd floor

Example: TDOA positioningExample: TDOA positioning

Initial resultsPosition estimates obtained with Ptx < 0.1 mWLow frequencies yields lower variance and biasLarge bias for some measurements

Error sources: time synchronization, multipath, interference(?)

TDOA – direct wave not necessarily the first correlation peakAbout 10 % erroneuous peaks was chosen

Continued workTOA-algorithms for multipath-resistant range estimationIncreased bandwidths – up to 100 MHzSoftware-defined radio approach for combined radio-based positioning, GPS and communications

GNU-radio software with ESRP-hardware?

Initial resultsPosition estimates obtained with Ptx < 0.1 mWLow frequencies yields lower variance and biasLarge bias for some measurements

Error sources: time synchronization, multipath, interference(?)

TDOA – direct wave not necessarily the first correlation peakAbout 10 % erroneuous peaks was chosen

Continued workTOA-algorithms for multipath-resistant range estimationIncreased bandwidths – up to 100 MHzSoftware-defined radio approach for combined radio-based positioning, GPS and communications

GNU-radio software with ESRP-hardware?