investigations of single antenna gps spoof...
TRANSCRIPT
http://commons.wikimedia.org/wiki/File:GPS-IIRM.jpg
Investigations of Single Antenna GPS Spoof
Detection !
Stanford University Global Positioning System Research
Laboratory with support from the FAA
WAAS program office !!
Emily McMilin, David De Lorenzo!Todd Walter, Thomas Lee,!
Per Enge!Oct 28, 20141
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Outline!• Motivation!
• Purpose of talk!• Why vulnerable?!• Practical threats?!• Why detection?!• Dynamic patterns!
• Detection!• Design!• Measurement!• Patterns!• Simulation!
• Hybrid!• Full!
• Conclusion
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Outline!• Motivation!
• Purpose of talk!• Why vulnerable?!• Practical threats?!• Why detection?!• Dynamic patterns!
• Detection!• Design!• Measurement!• Patterns!• Simulation!
• Hybrid!• Full!
• Conclusion
Today, I am going to show you a GPS spoof-detection antenna that is:!!
•Simple -- no math equations needed!•Static -- no movement needed!•Instantaneous -- no need to wait!•Small -- no larger footprint/radome required!•Backwards compatible -- no new receiver needed! (however receiver integration permits seamless functionality) !!
And it is also:!•Limited -- most effective in aerial applications
Motivation: Purpose of this presentation
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Motivation: Purpose of this presentation
Well-suited to constraints of aerial applications:
Form-factor constraints
Payload constraints
http://copter.ardupilot.com/wiki/advanced-multicopter-design/5http://xfaststyle.deviantart.com/art/AirPlane-198280783
!
•Our technique for achieving this type of adaptability in small single antenna systems is by integrating discrete circuit components on or near the antenna.!!
• these circuit components manipulating signals in the RF domain can achieve analog “signal processing” directly on the antenna.!
!
•essentially eliminating additional computational complexity !
!
•However, signal processing in the digital domain often affords far more flexibility and applicability.!
Motivation: Purpose of this presentation
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Outline!• Motivation!
• Purpose of talk!• Why vulnerable?!• Practical threats?!• Why detection?!• Dynamic patterns!
• Detection!• Design!• Measurement!• Patterns!• Simulation!
• Hybrid!• Full!
• Conclusion
Image credit: Tyler Reid, 2014
Medium Earth Orbit ~20,000 km
Motivation: Why is GPS so vulnerable?
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27 Watts
Motivation: Why is GPS so vulnerable?
9 Image credit: Tyler Reid, 2014
27 Watts
Motivation: Why is GPS so vulnerable?
10 Image credit: Tyler Reid, 2014
Motivation: Why is GPS so vulnerable?
158 attoWatts27 Watts
11 Image credit: Tyler Reid, 2014
Motivation: Why is GPS so vulnerable?
158 attoWatts27 Watts
12 Image credit: Tyler Reid, 2014
Motivation: Why is GPS so vulnerable?
0.5 Watts
158 attoWatts27 Watts
13 Image credit: Tyler Reid, 2014
Motivation: Why is GPS so vulnerable?
0.5 Watts158 attoWatts
27 Watts
14 Image credit: Tyler Reid, 2014
Motivation: Why is GPS so vulnerable?
0.5 Watts158 attoWatts
27 Watts
1.58 picoWatts
15 Image credit: Tyler Reid, 2014
Motivation: Why is GPS so vulnerable?
0.5 Watts158 attoWatts
27 Watts
1.58 picoWatts
1.58 pW : 158 aW10,000 :1
terrestrial : GPS SV
16 Image credit: Tyler Reid, 2014
http://commons.wikimedia.org/wiki/File:GPS-IIRM.jpg
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Outline!• Motivation!
• Purpose of talk!• Why vulnerable?!• Practical threats?!• Why detection?!• Dynamic patterns!
• Detection!• Design!• Measurement!• Patterns!• Simulation!
• Hybrid!• Full!
• Conclusion
Motivation: Why is GPS so vulnerable?Motivation: What are the practical threats?
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Motivation: What are the practical threats?
19
Motivation: What are the practical threats?
20
Motivation: What are the practical threats?
21
Motivation: What are the practical threats?
22
Motivation: What are the practical threats?
23
http://commons.wikimedia.org/wiki/File:GPS-IIRM.jpg
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Outline!• Motivation!
• Purpose of talk!• Why vulnerable?!• Practical threats?!• Why detection?!• Dynamic patterns!
• Detection!• Design!• Measurement!• Patterns!• Simulation!
• Hybrid!• Full!
• Conclusion
Spoofer spoofing
Goal is to mislead and avoid detection
Motivation: Why detection?
25
25
Spoofer spoofing
Goal is to mislead and avoid detection
Motivation: Why detection?
detection
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26
Spoofer spoofing
Goal is to mislead and avoid detection
Motivation: Why detection?
detection
Spoofer jamming
Result is a costly jamming operation
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27
Spoofer spoofing
Goal is to mislead and avoid detection
Motivation: Why detection?
detection
Spoofer jamming
Result is a costly jamming operation
elapsed time
28
28
Spoofer spoofing
Goal is to mislead and avoid detection
Motivation: Why detection?
detection
Spoofer jamming
Result is a costly jamming operation
elapsed time
Spoofer exposed
:)
29
29
http://commons.wikimedia.org/wiki/File:GPS-IIRM.jpg
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Outline!• Motivation!
• Purpose of talk!• Why vulnerable?!• Practical threats?!• Why detection?!• Dynamic patterns!
• Detection!• Design!• Measurement!• Patterns!• Simulation!
• Hybrid!• Full!
• Conclusion
Motivation: Dynamic radiation patterns
normal-mode 31
Motivation: Dynamic radiation patterns
normal-mode 32
Motivation: Dynamic radiation patterns
normal-mode
Signal coming
from satellites
or spoofers?
33
detection-mode
Motivation: Dynamic radiation patterns
34
If receive signal strength goes down,
then you were tracking a satellite.
detection-mode
If SNR goes down, then tracking a satellite.
Motivation: Dynamic radiation patterns
35
If receive signal strength goes up,
then you were! tracking a spoofer!
If SNR goes up, then
tracking a spoofer.
Motivation: Dynamic radiation patterns
detection-mode 36
If receive signal strength goes up,
then you were! tracking a spoofer!
Motivation: Dynamic radiation patterns
detection-mode
But it turns out it is not
so easy.
37
Motivation: Our question
If we assume:!!
•GPS signals are originating from the upper hemisphere!•Spoofed signals are originating from the lower hemisphere,!!
can we achieve detection?
38
Motivation: ...but first, how?
How to achieve "detection-mode" radiation pattern?!•Create an large array aperture that can swing a beam to lower hemisphere angles?!•Mechanically flip the antenna upside-down?!!
Simple, static, instantaneous and backward compatible solution?!•No, so we will not be able to replicated the upper hemisphere pattern in the lower hemisphere, but can we find something comparable?
39
Motivation: a smaller question
How to achieve "detection-mode"?!•Create an large array aperture that can swing a beam to lower hemisphere angles?!•Mechanically flip the antenna upside-down?!!
Are these simple, static, instantaneous and backward compatible solutions?!•No, so we will not be able to replicate the upper hemisphere pattern in the lower hemisphere!
•Can we find something comparable?
40
Motivation: a smaller question
How to achieve "detection-mode"?!•Create an large array aperture that can swing a beam to lower hemisphere angles?!•Mechanically flip the antenna upside-down?!!
Are these simple, static, instantaneous and backward compatible solutions?!•No, so we will not be able to replicate the upper hemisphere pattern in the lower hemisphere!
•Can we find something comparable?
41
http://commons.wikimedia.org/wiki/File:GPS-IIRM.jpg
Outline!!
• Motivation!• Detection!• Design!• Measurement!• Patterns!• Simulation!
• Hybrid!• Full!
• Conclusion42
Looking to typical GPS antennas for inspiration
Detection
43
Detection: Typical GPS antenna
GPS/GNSS Antennas. By B. Rama Rao, W. Kunysz, R. Fante and K. McDonald, Artech House, 201244
Detection: Typical GPS antenna
GPS/GNSS Antennas. By B. Rama Rao, W. Kunysz, R. Fante and K. McDonald, Artech House, 2012
Typical RHCP pattern!Typical LHCP pattern!
45
Detection: Typical GPS antenna
Typical RHCP pattern!Typical LHCP pattern!
GPS/GNSS Antennas. By B. Rama Rao, W. Kunysz, R. Fante and K. McDonald, Artech House, 2012
Normal-mode:!!
46
Detection: Typical GPS antenna to satellites
Normal-mode:!GPS satellites see this RHCP pattern
GPS/GNSS Antennas. By B. Rama Rao, W. Kunysz, R. Fante and K. McDonald, Artech House, 201247
Detection: Typical GPS antenna to satellites
Detection-mode:!GPS satellites see this RHCP pattern
GPS/GNSS Antennas. By B. Rama Rao, W. Kunysz, R. Fante and K. McDonald, Artech House, 201248
Normal-mode >> Detection-mode!for GPS satellites
Detection: Typical GPS antenna to satellites
GPS/GNSS Antennas. By B. Rama Rao, W. Kunysz, R. Fante and K. McDonald, Artech House, 201249
Normal-mode:!Spoofers see this
RHCP pattern
Detection: Typical GPS antenna to spoofers
GPS/GNSS Antennas. By B. Rama Rao, W. Kunysz, R. Fante and K. McDonald, Artech House, 201250
Detection-mode:!Spoofers see this
RHCP pattern
Detection: Typical GPS antenna to spoofers
GPS/GNSS Antennas. By B. Rama Rao, W. Kunysz, R. Fante and K. McDonald, Artech House, 201251
emtodo RESEARCH ON GPS ANTENNAS AT MITRE, B. Rama Rao, M. N.Solomon, M. D.Rhines, L. J. Teig, R. J. Davis, E.N.Rosario, The MITRE Corporation
Detection: Typical GPS antenna to spoofers
GPS/GNSS Antennas. By B. Rama Rao, W. Kunysz, R. Fante and K. McDonald, Artech House, 2012
Normal-mode ~= Detection-mode!for Spoofers
52
emtodo RESEARCH ON GPS ANTENNAS AT MITRE, B. Rama Rao, M. N.Solomon, M. D.Rhines, L. J. Teig, R. J. Davis, E.N.Rosario, The MITRE Corporation
Detection: Typical GPS antenna
Normal-mode >> Detection-mode!for GPS satellites
If SNR goes down, then tracking a satellite.
GPS/GNSS Antennas. By B. Rama Rao, W. Kunysz, R. Fante and K. McDonald, Artech House, 2012
Normal-mode ~= Detection-mode!for Spoofers
53
emtodo RESEARCH ON GPS ANTENNAS AT MITRE, B. Rama Rao, M. N.Solomon, M. D.Rhines, L. J. Teig, R. J. Davis, E.N.Rosario, The MITRE Corporation
Detection: Typical GPS antenna
Normal-mode >> Detection-mode!for GPS satellites
If SNR goes down, then tracking a satellite.
If SNR stays ~flat, then tracking a spoofer.
GPS/GNSS Antennas. By B. Rama Rao, W. Kunysz, R. Fante and K. McDonald, Artech House, 2012
Normal-mode ~ Detection-mode!for Spoofers
54
emtodo RESEARCH ON GPS ANTENNAS AT MITRE, B. Rama Rao, M. N.Solomon, M. D.Rhines, L. J. Teig, R. J. Davis, E.N.Rosario, The MITRE Corporation
Detection: Typical GPS antenna
Normal-mode >> Detection-mode!for GPS satellites
If SNR goes down, then tracking a satellite.
If SNR stays ~flat, then tracking a spoofer.
GPS/GNSS Antennas. By B. Rama Rao, W. Kunysz, R. Fante and K. McDonald, Artech House, 2012
Normal-mode ~ Detection-mode!for Spoofers
55
We can exploit this telltale drop in the received SNR or C/N0 to confirm the
signal is originating from above
a
Detection: Typical GPS antenna
GPS/GNSS Antennas. By B. Rama Rao, W. Kunysz, R. Fante and K. McDonald, Artech House, 201256
a = upper hemisphere difference between
RHCP and LHCP (dB)
aa = cross polarization discrimination (XPD)
Detection: Typical GPS antenna
GPS/GNSS Antennas. By B. Rama Rao, W. Kunysz, R. Fante and K. McDonald, Artech House, 201257
aa = upper hemisphere
difference between RHCP and LHCP (dB)
Detection: Typical GPS antenna
GPS/GNSS Antennas. By B. Rama Rao, W. Kunysz, R. Fante and K. McDonald, Artech House, 201258
"Typical" GPS antenna patterns
a
b = lower hemisphere difference between
RHCP and LHCP (dB) b
Detection: Typical GPS antenna
GPS/GNSS Antennas. By B. Rama Rao, W. Kunysz, R. Fante and K. McDonald, Artech House, 201259
a = upper hemisphere difference between
RHCP and LHCP (dB)
"Typical" GPS antenna patterns
a
b = lower hemisphere difference between
RHCP and LHCP (dB) b
Detection: Typical GPS antenna
GPS/GNSS Antennas. By B. Rama Rao, W. Kunysz, R. Fante and K. McDonald, Artech House, 201260
a = upper hemisphere difference between
RHCP and LHCP (dB)In most GPS antennas a >> b. Thus, this often derided, yet unavoidable back-
lobe radiation becomes our ally.
http://commons.wikimedia.org/wiki/File:GPS-IIRM.jpg
Outline!!
• Motivation!• Detection!• Design!• Measurement!• Patterns!• Simulation!
• Hybrid!• Full!
• Conclusion61
x-axis port and x-axis
field
y-axis port and y-axis
field
Design: Circular Polarization
62
x-axis port and x-axis field
y-axis field lags by 90 deg
Design: Predominately RHCP! !
y-axis port and y-axis field
RHCP
LHCP63
RHCP
LHCP
Design: Predominately RHCP! !
y-axis field lags by 90 deg
x-axis port and x-axis field
y-axis port and y-axis field
normal-mode
64
RHCP
LHCP
Design: Predominately RHCP ! !
LHCP
normal-mode
RHCP
y-axis field lags by 90 deg
x-axis port and x-axis field
y-axis port and y-axis field
65
RHCP
Design: Predominately LHCP! !LHCP
x-axis field lags by 90 deg
x-axis port and x-axis field
y-axis port and y-axis field
66
RHCP
Design: Predominately LHCP! !LHCPdetection-mode
x-axis field lags by 90 deg
x-axis port and x-axis field
y-axis port and y-axis field
67
Design: Predominately LHCP! !detection-mode
x-axis field lags by 90 deg
LHCP
RHCP
RHCP
LHCP
x-axis port and x-axis field
y-axis port and y-axis field
68
RHCP
LHCP
Design: Predominately RHCP ! !
LHCP
normal-mode
RHCP
y-axis field lags by 90 deg
x-axis port and x-axis field
y-axis port and y-axis field
69
Design: Predominately LHCP! !detection-mode
x-axis field lags by 90 deg
LHCP
RHCP
RHCP
LHCP
x-axis port and x-axis field
y-axis port and y-axis field
70
Design: Predominately LHCP! !detection-mode
x-axis field lags by 90 deg
LHCP
RHCP
RHCP
LHCP
x-axis port and x-axis field
y-axis port and y-axis field
Main idea: switching back and forth between these two modes and watching for the telltale drop in the received SNR or C/N0.
71
90 degree hybrid coupler 50 ohm resister
antenna
Design: Basic GPS antenna
radio
72
90 degree hybrid coupler 50 ohm resister
antenna
DPDT switch
Design: GPS spoof detection antenna
Executive Function
Normal-mode
Detection-mode
radio
73
90 degree hybrid coupler 50 ohm resister
antenna
radio
DPDT switch
Design: GPS spoof detection antenna
Executive Function
Normal-mode
Detection-mode
b
c
d
e
a.x a.y
d
a.x a.y
74
b
ce
d
a.x a.y
Design: GPS spoof detection schematic
Note: • Simulation done with Agilent's
Advanced Design System (ADS) software
• Switching DC logic circuit and Executive function not shown.
75
a.x
d
a.y
a.y
a.x
d
Normal-mode: Port 4 lags by -90 deg phase shift
S-param!magnitude
S-param!phase
frequency
frequency
76
a.x
a.y
d
a.xa.y
d
S-param!magnitude
S-param!phase
frequency
frequencyDetection-mode: Port 3 lags by -90 deg phase shift77
a.x
d
a.y
a.y
a.x
d
Normal-mode: Port 4 lags by -90 deg phase shift
S-param!magnitude
S-param!phase
frequency
frequency
78
a.x
d
a.y
a.y
a.x
d
Normal-mode: Port 4 lags by -90 deg phase shift
S-param!magnitude
S-param!phase
frequency
frequency
79
Phase "jitter" less than 4 degrees
a.x
d
a.y
a.y
a.x
d
Normal-mode: Port 4 lags by -90 deg phase shift
S-param!magnitude
S-param!phase
frequency
frequency
80
Total insertion loss: 0.7 dB
81
Design: Discrete components
bc
82
Design: Discrete components
bc
83
Design: Discrete components
bc
Both cost less than $1 in relatively small volume purchases
Design: Ceramic patch antennaIn order to test the spoof detection concept for various signal direction of arrivals (DoA), we needed an antenna's radiation pattern measurement data, including:!!
•Both RHCP and LHCP patterns!•Full back lobe pattern!!
It was not easy to find this information, so we decided on trying to make our own "typical" GPS patch antenna and conduct our own measurements.
84
Design: Ceramic patch antenna"Typical" is desirable because we are interested in as universal a solution as possible:!!
•Typical upper/lower hemisphere gain patterns!•Typical cross polarization description (XPD)!•Typical size (ARINC 743 compatible)!!
Even simple GPS antennas are optimized given an existing body of constrains, and the introduction of any new constraint will inevitably require trade-offs and a resulting performance degradation.
85
Design: Ceramic patch antenna
61mm x 61mm ground-plane
86
Design: Ceramic patch antenna
76mm x 76mm ground-plane
87
Design: Ceramic patch antenna
88
Design: Ceramic patch antenna
89
"Typical" GPS antennas also include quadrifilar helix antennas, crossed bow tie antennas, and any antenna that may
have multiple internal ports
http://commons.wikimedia.org/wiki/File:GPS-IIRM.jpg
Outline!!
• Motivation!• Detection!• Design!• Measurement!• Patterns!• Simulation!
• Hybrid!• Full!
• Conclusion90
*azimuth **elevation
Measurement! horn
**mount
*
foam
Measurement: Far field set-up
91
Measurement: Far field results
92
Measurement: Far field results
a = 7dB
b = 10dB
93
Measurement: Far field results
a = 7dB
b = 10dB
Turns out that "typical" is not that easy. The antenna we built does not meet some basic
GPS antenna requirements.
94
http://commons.wikimedia.org/wiki/File:GPS-IIRM.jpg
Outline!!
• Motivation!• Detection!• Design!• Measurement!• Patterns!• Simulation!
• Hybrid!• Full!
• Conclusion95
We revisited literature for simulated and measured patterns with full back lobe !RHCP/LHCP radiation patterns, to find
inspiration lacking in the antenna we built.
Patterns
96
Calculated pattern for GPS antenna in forward location
Calculated pattern for GPS antenna in aft location
Patterns: Typical GPS antenna on missile
RESEARCH ON GPS ANTENNAS AT MITRE, B. Rama Rao, M. N.Solomon, M. D.Rhines, L. J. Teig, R. J. Davis, E.N.Rosario, The MITRE Corporation97
Calculated pattern for GPS antenna in forward location
Calculated pattern for GPS antenna in aft location
a = 20dB a = 20dB
Patterns: Typical GPS antenna on missile
RESEARCH ON GPS ANTENNAS AT MITRE, B. Rama Rao, M. N.Solomon, M. D.Rhines, L. J. Teig, R. J. Davis, E.N.Rosario, The MITRE Corporation98
Calculated pattern for GPS antenna in forward location
Calculated pattern for GPS antenna in aft location
a = 20dB a = 20dB
b = 0dB b = 0dB
Patterns: Typical GPS antenna on missile
RESEARCH ON GPS ANTENNAS AT MITRE, B. Rama Rao, M. N.Solomon, M. D.Rhines, L. J. Teig, R. J. Davis, E.N.Rosario, The MITRE Corporation99
Patterns: Typical GPS antenna on plane
"Measurements on a GPS Adaptive Antenna Array Mounted on a 1/8-Scale F-16 Aircraft," Rao, B. Rama, Williams, Jonathan H., Proceedings of the 11th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GPS 1998)100
a = 20dB
Patterns: Typical GPS antenna on plane
"Measurements on a GPS Adaptive Antenna Array Mounted on a 1/8-Scale F-16 Aircraft," Rao, B. Rama, Williams, Jonathan H., Proceedings of the 11th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GPS 1998)101
a = 20dB
b = 0dB
Patterns: Typical GPS antenna on plane
"Measurements on a GPS Adaptive Antenna Array Mounted on a 1/8-Scale F-16 Aircraft," Rao, B. Rama, Williams, Jonathan H., Proceedings of the 11th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GPS 1998)102
a = 20dB
b = 0dB
ripple = 10dB
Patterns: Typical GPS antenna on plane
"Measurements on a GPS Adaptive Antenna Array Mounted on a 1/8-Scale F-16 Aircraft," Rao, B. Rama, Williams, Jonathan H., Proceedings of the 11th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GPS 1998)103
http://commons.wikimedia.org/wiki/File:GPS-IIRM.jpg
Outline!!
• Motivation!• Detection!• Design!• Measurement!• Patterns!• Simulation!
• Hybrid!• Full!
• Conclusion104
http://commons.wikimedia.org/wiki/File:GPS-IIRM.jpg
Hybrid Simulation: System Design
How to achieve backward capability with existing GPS receivers? !!
•No new processing blocks can be added:!•Exploit only minimum required set of existing functionality blocks.!•Report spoof-detection results using existing reporting framework: C/N0 or SNR!
105105
Detection-mode
Normal-modeRadio Executive
Function
Antenna
Hybrid Simulation: Overview
106
Hybrid Simulation: Overview
Detection-mode
Normal-modeRadio Executive
Function
Antenna
Far field!measurement
data setPython scripts
107
Detection-mode
Normal-modeRadio Executive
Function
Antenna
Hybrid Simulation: Overview
We assume an intelligent spoofer that has adjusted their transmit strength to reasonably
overpower LOS signal from GPS satellites.
108
Detection-mode
Normal-modeRadio Executive
Function
Antenna
Hybrid Simulation: Overview
109
Normal-modeRadio Executive
Function
Antenna
time
Hybrid Simulation: Overview
TDefault
Normal-mode
110
Detection-mode
Normal-modeRadio Executive
Function
Antenna
time
Hybrid Simulation: Overview
TDefault TMonitor
Normal-mode
Detection!-mode
TN
TD
111
Detection-mode
Normal-modeRadio Executive
Function
Antenna
time
Hybrid Simulation: Overview
TDefault
Normal-mode
Detection!-mode
TMonitor
TN
TD
TCoh
coherent integration period
112
Detection-mode
Normal-modeRadio Executive
Function
Antenna
time
Hybrid Simulation: Overview
TDefault
Normal-mode
Detection!-mode
TCoh
TMonitor
TN
TD
coherent integration period
113
Tracking seven GPS satellites
114
Tracking seven GPS satellites
115
A single spoofing source
116
A single spoofing source
117
Two spoofing sources
118
http://commons.wikimedia.org/wiki/File:GPS-IIRM.jpg
Outline!!
• Motivation!• Detection!• Design!• Measurement!• Patterns!• Simulation!
• Hybrid!• Full!
• Conclusion119
Full Simulation: Overview
Detection-mode
Normal-modeRadio Executive
Function
Antenna
Simulated far field measurement !
data setPython scripts
120
121
122
a = 13dB
b = 5dB
123
ripple = 15dB
a = 13dB
b = 5dB
124
Using simulated antenna data
125
5 dB
13 dB
126
15 dB
126
Using simulated antenna data
127
http://commons.wikimedia.org/wiki/File:GPS-IIRM.jpg
Outline!!
• Motivation!• Detection!• Design!• Measurement!• Patterns!• Simulation!
• Hybrid!• Full!
• Conclusion128
b
aa
Conclusion: Limitations
Requirement for detection:!•If we can assume SVs are above and spoofers are below:!•a >> b, for at least one satellite signal DoA!
!•If we can not assume SVs are above and spoofers are below:!•we can exploit characteristics unique to each DoA such as XPD ripple
ripple
129
We have designed an antenna that uses analog “signal processing” to perform simple, low cost, backwards compatible and instantaneous spoof-detection for aerial applications.
Conclusion
130
Special thanks to Paul Miller, Sunali Chokshi, Martin
McBride, Larry Arnett, Claudia Lam and Chris Hoeber at
Space Systems/Loral.!!
Also thanks to Dennis Akos at University of Colorado!!
131
Thank you for your time!!!
132
Y.-H. Chen, S. Lo, D. Akos, D. S. De Lorenzo, P. Enge, ``Validation of a Controlled Reception Pattern Antenna (CRPA) Receiver Built From Inexpensive General-purpose Elements During Several Live-jamming Test Campaigns,"Proceedings of the 2013 International Technical Meeting of The Institute of Navigation, San Diego, California, January 2013, pp. 154-163. !P. Montgomery and T. E. Humphreys, ``A Multi-Antenna Defense: Receiver-Autonomous GPS Spoofing Detection," Inside GNSS, no. March/April, pp. 40-46, 2009. !A. Konovaltsev, M. Cuntz, C. Haettich, M. Meurer, ``Performance Analysis of Joint Multi-Antenna Spoofing Detection and Attitude Estimation," Proceedings of the 2013 International Technical Meeting of The Institute of Navigation, San Diego, California, January 2013, pp. 864-872. !J. Nielsen, A. Broumandan,G. Lachapelle, ``GNSS Spoofing Detection for Single Antenna Handheld Receivers", NAVIGATION, Journal of The Institute of Navigation, Vol. 58, No. 4, Winter 2011-2012, pp. 335-344. !M. L. Psiaki, S. P. Powell, B. W. O'Hanlon, ``GNSS Spoofing Detection using High-Frequency Antenna Motion and Carrier-Phase Data," Proceedings of the 26th International Technical Meeting of The Satellite Division of the Institute of Navigation (ION GNSS+ 2013), Nashville, TN, September 2013, pp. 2949-2991. !F. N. Bauregger, T. Walter, D. Akos, P. Enge, ``A Novel Dual Patch Anti Jam GPS Antenna," Proceedings of the 58th Annual Meeting of The Institute of Navigation and CIGTF 21st Guidance Test Symposium, Albuquerque, NM, June 2002, pp. 516-522. !B. Rama Rao, W. Kunysz, R. L. Fante and K. F. McDonald, in GPS/GNSS Antennas, Artech House, 2013 !B. Rama Rao, J. H. Williams, ``Measurements on a GPS Adaptive Antenna Array Mounted on a 1/8-Scale F-16 Aircraft," Proceedings of the 11th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GPS 1998), Nashville, TN, September 1998, pp. 241-250. !B. Rama Rao, M. N. Solomon, M. D. Rhines, L. J. Teig, R. J. Davis, E.N.Rosario, ``Research on GPS Antennas at MITRE'', Position Location and Navigation Symposium, IEEE 1998 , vol., no., pp.634,641, 20-23 Apr 1998
References