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
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?