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Logan Scott, President, LS [email protected]
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Sponsored By:
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Rohde & SchwarzThe expert in
test and measurement,broadcasting,secure communications,radiomonitoring and radiolocation
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Company profile and GNSS expertise | 3
Company overview
l HistoryEstablished 1933 in Munich, Germany
l Type of enterpriseIndependent family-owned company
l Global presenceIn over 70 countries, approx. 60 subsidiaries
l Net revenueEUR 1.8 billion (FY 11/12, July through June)
l Export shareApprox. 90 percent
l Employees8700 worldwide, with approx. 5600 in Germany
l SuccessA leading international supplier in all of its business fields
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Company profile and GNSS expertise | 4
Business fields
Test and measurement
Broadcasting
Secure
communications
Radiomonitoring and
radiolocation
Services
All business fields
contribute to the
aerospace and
defense sector
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Company profile and GNSS expertise | 5
Simulating GNSS scenarios
l GPS(C/A and P code), Glonass and Galileo
l Up to 24 satellites for hybrid scenarios and multipathsimulation
l Static and moving receiver simulation with predefined
trajectories and HIL for realtime movement definition
l Simulation of real-world scenarios, including
l Ionospheric and tropospheric effectsl Obscuration and automatic multipath through vertical obstacles
(rural, suburban, urban canyons, etc.)
l Antenna pattern / body mask for cars, aeronautical and military
vehicles/objects plus antenna characteristics
l Spinning and attitude for A&D applications
l General purpose vector signal generatorsupporting many other standards
Features in italics coming soon
R&SSMBV100A
vector signal generator
with GNSS options
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Company profile and GNSS expertise | 6
Detection and location of GPS/GNSS interferers
l Detect and find interference
l R&SPR100 portable
receiver
l Manual direction findingTriangulation on a map as option
l Locate interference quickly and precisely
l R&SDDF007 portable direction finderAutomatic direction finding with compact DDF
antennas; car-mobile or stationary
l R&SRAMON mobile locatorAutomatic PC homing software for the
R&SDDF007
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Company profile and GNSS expertise | 7
For details, see www.rohde-schwarz.com
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Logan Scott, President, LS [email protected]
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Sponsored By:
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GPS Jamming and Spoofing (Military)
Denial of Navigation to Opposing Forces
Create Confusion / Lessen Effectiveness
GPS Jamming and Spoofing (Civil)
Accidental Deliberate
Financial Exploit (More Likely Reason)
Terroristic Exploit (Less Likely Reason)
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Jammings Objective Denial of Navigation Service by Masking GPS Signals
With Noise
Tends Towards Area Denial
Spoofings Objective Convince You That You Are Somewhere or Sometime
You Are Not Overlaying Real Signals With False Signals
Cyber Attack (Lying) Usually Targets A Specific Victim
Structure Jamming Can Act Like UncontrolledSpoofing
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What are We Trying to Track?
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Block IIA/IIR Block IIIlock IIR-M, IIF
III: IIF capabilities & Improved civil signal (L1C)
Increased accuracy (4.8-1.2m)
Navigation surety
Increased A/J power (+20 dB)
IIA / IIR: Basic GPS C/A civil signal (L1C/A)
Std Service, 16-24m SEP
Precise Service, 16m SEP
L1 & L2 P(Y) nav
Modernization
IIR-M: IIA/IIR capabilities & 2nd civil signal (L2C)
New military code
Flex A/J power (+7dB)
IIF: IIR-M capability plus
3rd civil signal (L5)
GPS modernization balances military and civil needs
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?*
Block III will introduce the new L1C signal
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BPSK: Binary Phase Shift KeyingBOC: Binary Offset Carrier
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PropagationDelay
AA/demo_code.m
x
=
x
=
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fch = PN sequence chip rate rate
fc = RF center frequency
PN Code
Generator
fch
Sin(2pfct)
BPSK ModulatorPN(t)
spreading sequence
D(t)
data(Only on Data Channel)
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6 February 2013 Logan Scott / LS Consulting 18
fsqu = subcarrier frequency = square wave frequency
fch = PN sequence chip rate rate
fc = RF center frequency
1/fsqu
PN Code
Generator
fch
Sin(2pfct)
BPSK Modulator
squ(t)
PN(t)
D(t)
data
spreading sequence
Only on Data Channel
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From: Holmes and Dafish Matched Filter Mean Acquisition Time Performance For P(Y), BOC(10,5), and MAN(10)
Codes With FFT Aiding and Noncoherent Combining ION 57th Annual Meeting/CIGTF 20th Biennial Guidance
Test Symposium, 11-13 June 2001, Albuquerque, NM
x
=
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f0 = 10,230,000 Hz
f1 = f0/10 = 1,023,000 Hz
fsqu = m * f1fch = n * f1
M-code is BOC(10,5) fsqu = 10 * f1 = 10,230,000 Hz
fch = 5 * f1 = 5,115,000 Hz
P(Y)-code is BPSK(10)
fch = 10 * f1 = 10,230,000 Hz
C/A-code is BPSK(1)
fch = 1 * f1 = 1,023,000 Hz
L1 Center Frequency
fc = 154 * f0 =1575.42 MHz
L2 Center Frequency
fc = 120 * f0 =1227.60 MHz
L5 Center Frequency
fc = 115 * f0 =1176.45 MHz
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6 February 2013 Logan Scott / LS Consulting 21
M-Code
P(Y)-Code
L1C*
C/A-Code
*L1C also has a BOC(6,1) Component (Not Shown)
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6 February 2013 Logan Scott / LS Consulting 22
Signal Format Table.xlsx
Signal Availability
Spectral
Format
First Supporting
Satellite
Generation
Current Number of
Satellites
Transmitting This
Signal
L1 C/A Civil BPSK(1) All 32
L1C Civil BOC(1,1) III 0
L1 P(Y) Military BPSK(10) All 32
L1 M Military BOC(10,5) IIR-M 10
L2C Civil BPSK(1) IIR-M 10L2 P(Y) Military * BPSK(10) All 32
L2 M Military BOC(10,5) IIR-M 10
L5 Civil BPSK(10) IIF 3
L1C also has a BOC(6,1) Component / * L2Y is used in some civil applications
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6 February 2013 Logan Scott / LS Consulting 23
BPSK Spectral Properties
Equivalent Noise Bandwidth fch
2
sin
)(
f
ff
ffSch
chBPSKp
p
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6 February 2013 Logan Scott / LS Consulting 24
2
2
cos
sin2
sin
)(
squ
chsqu
chBOC
f
ff
ff
ff
ffSp
p
pp
BOC Spectral Properties (fsqu = k fch)
Equivalent Noise Bandwidth 2.0 fch for fsqu > 2fchEquivalent Noise Bandwidth 1.6 fch for fsqu = fch
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GPS Signal Type(s) Used Signal Spectrum L1 C/A has Structure Vulnerabilities
Jamming Type / Spectrum Radio Propagation Factors
Jamming Mitigation Factors External Sensor Aiding Configuration
Loose vs. Tight vs. Ultratight Coupling Antenna Patterns & Adaptation Performance Frequency and/or Time Domain Excision Backups/Alternative Signals
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6 February 2013 Logan Scott / LS Consulting 27
Brute Force Jamming
Noise Broadband unstructured
signal intended to
swamp the receiver Spectrum matched
jammer is most effective
CW A constant tone (typically
at or near L1) intended toforce loss of lock ondesired signal
Smart/intelligent Jamming*
Pulsed Noise or Pulsed CW Jammer achieves higher peak power for same
average power; keeps receiver off-balance Attacks AGC, tracking loops & data reading
Swept Tone (against L1 C/A) Captures carrier loop; pulls it off-center Can capture all receiver channels regardless of
Doppler; can exploit C/A code spectral lines
Gold Code (against L1 C/A) Takes Advantage of Gold Code Crosscorrelation
Properties
*Methods to jam more efficiently with same average power constraint.
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6 February 2013 Logan Scott / LS Consulting 28
PN Code
Generator Sin(2pfct)
Satellite
PN(t)
D(t)
data
PN Code
GeneratorReceiver
PN(t-t)D(t)
data
50 Hz
BPF
Sin(2pfct)
Jammer
2
1
3
4
5
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1
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2
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3
Jammer PSD
Signal PSD
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4
Jammer PSD
Signal PSD
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5
Jammer PSD
50 Hz
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6 February 2013 Logan Scott / LS Consulting 34
P-Code C/A Code
Signal Chipping Rate (Hz) 10,230,000 1,023,000
Equivalent Noise Bandwidth (Hz) 10,230,000 1,023,000
Post Code Mixing CW Jammer Bandwidth (Hz) 10,230,000 1,023,000
Data Filter Bandwidth (Hz) 50 50
Fraction of Jammer Energy That Gets Through
Data Filter 50 / 10,230,000 50 / 1,023,000
= =
1 / 204,600 1 / 20,460
How Much Stronger Jammer Has To Be Relative
to Signal to Yield Equal Post Correlation Power 204,600 20,460Required Post Correlation Ratio of Signal
Strength to Jammer Strength Needed to Track 10 10
How Much Stronger Jammer Can Be Relative to
Signal And Can Track (J/S numeric) 20,460 2,046
J/S (dB) = 10 log10 (J/S numeric) 43.1 33.1
ProcessingGain
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C/A CodeTemporalSidelobes
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C/A Code RepeatsItself with 1 msec
Period So Lines are 1kHz Apart
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PRN 3 Response
acq/stage1i.m
6 February 2013
TrackingLoops CanLock on To
These
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6 February 2013 Logan Scott / LS Consulting 41
Affects Only C/A code Reception Can Adversely Affect Military Receiver Signal Acquisition
Autocorrelation Value Probability
0 dB wrt peak-23.9 dB wrt peak
-24.2 dB wrt peak
-60.2 dB wrt peak
0.098 %12.5%
12.5%
75%
C/A Code Periodic Autocorrelation Values (Integer Code Phase Offsets)
C/A Code Periodic Cross-Correlation Values (Integer Code Phase Offsets)
Cross CorrelationValue
Probability
-23.9 dB wrt peak
-24.2 dB wrt peak
-60.2 dB wrt peak
12.5%
12.5%
75%
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Logan Scott / LS Consulting 42
PRN 3 Response
acq/stage1i.m
6 February 2013
TrackingLoops CanLock on To
These
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PRN 3 Response PRN 3 Response
PRN 3 Response PRN 3 Response
No Jamming Gaussian Jamming
CW Jamming PRN1 Jamming
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PRN 3 Response
No Jamming
PRN 3 Response
PRN1 Jamming (J/S=24)
PRN 3 Response
PRN1 Jamming (J/S=24)
PRN 3 Response
No Jamming
L1C/A
L1C
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Logan Scott / LS Consulting 45
PRN 3 Response
acq/stage1i.m
6 February 2013
L1COOverlayCode will Make
False PeaksEphemeral; YouWont Lock onto
Them
Can Still BeJammed
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Accounting for Signal And Interference Spectral Shapes
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M-Code
P(Y)-Code
L1C*
C/A-Code
*L1C also has a BOC(6,1) Component (Not Shown)
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6 February 2013 Logan Scott / LS Consulting 48
After: John W. Betz, Effect of Narrowband Interference on GPS Code TrackingAccuracy, presented at ION NTM 2000, 26-28 January 2000, Anaheim, CA
2/
2/
2/
2/
0
2/
2/
0
)()()(
)(
r
r
r
r
r
r
dffGfGCdffGN
dffGC
IN
C
N
C
stts
ss
effective
I Use NumericalIntegration to Evaluate
This Equation
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6 February 2013 Logan Scott / LS Consulting 49
DensitySpectralPowerNoiseThermal:N
PowerJammerReceived:
1)(
SpectrumPowerNormalizedsJammer':)(
PowerSignalReceived:
1)(
SpectrumPowerNormalizedsSignal':)(
0
t
t
t
s
s
s
C
dffG
fG
C
dffG
fG
C/NonumericN
C
(Hz)BandwidthFilterEndFront
(sec)SeparationEarly/Late
(sec)timenintegratioonpredetectiT
(Hz)bandwidthloopcodeB
o
r
L
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Incident J /SP
(dB wrt S=-160.5 dBW)
EffectiveC/N0
(dB
-Hz)
All Cases:Tant.
=130K, NF=2 dB, L=1 dB,
Gsig
=0dBiC, Gjam
=0dBiC ,24 MHz Passband
M-code
P(Y)-code
C/A-code
Assuming NoReceiver
Saturation!
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M-Code
P(Y)-Code
L1C*
C/A-Code
*L1C also has a BOC(6,1) Component (Not Shown)
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Incident J /SP
(dB wrt S=-160.5 dBW)
EffectiveC/N0
(dB
-Hz)
All Cases:Tant.
=130K, NF=2 dB, L=1 dB,
Gsig
=0dBiC, Gjam
=0dBiC ,24 MHz Passband
M-code
P(Y)-code
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6 February 2013 Logan Scott / LS Consulting 53
Incident J /SP
(dB wrt S=-160.5 dBW)
EffectiveC/N0
(dB
-Hz)
All Cases:Tant.
=130K, NF=2 dB, L=1 dB
Gsig
=0dBiC, Gjam
=0dBiC ,24 MHz Passband
M-code
C/A-code
P-code
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The Role of Propagation and Jamming Type
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Appropriate under Line Of SightConditions (1st Fresnel Zone) Rarely Appropriate in Ground Mobile Analysis
Sreceived = Stransmitted + Gt + Gr + 20 log10(/4R)
where:
Sreceived is received signal power (dBW)
Stransmitted is transmitted signal power (dBW)
Gt is transmitter antenna gain in the direction of the receiver (dBiC)
Gr is receiver antenna gain in the direction of the transmitter (dBiC)
is the signals wavelength (19 cm @ L1, 24 cm @ L2)
R is spatial Tx/Rx separation in same units as wavelength
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0
10
20
30
40
50
60
70
80
90
100
1 10 100 1000
Range (km)
J/S (dB wrt -133
dBm Signal)
1000 Watt EIRP
100 Watt EIRP
10 Watt EIRP
1 Watt EIRP
Nominal Unaided P-code
Receiver J/S Threshold
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C/A Code Signal
M Code Signal
P(Y) Code Signal
28 dB-Hz
NominalPhaselockThreshold
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Reflected Path Can Add to Direct Path Either Destructively or ConstructivelyDepending on Geometry
At Longer Ranges, Signal Strength Falls Off at R4 Rate
Can Also Apply In Ground Jammer to Airborne Receiver Cases
Ground
DirectPath
ReflectionPath
Transmitter
Receiver
Two Ray Propagation Model
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fresnel3.m
Two RayModel
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Hata/Okumura Empirical Signal Strength Models
Modified Models Are Described In ETSI GSM 03.30
Considers Six Types of Area:
Large City Open Area Large City Suburban
Large City Urban
Small City Open Area
Small City Suburban
Small City Urban
Mission Planning Tools Such as GIANT (GPS Interference And NavigationTool) Can Accurately Model Jamming Coverage
Includes Topographic Data Base
Can Model Combined Multiple Jammer Effectiveness
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100
101
102
-20
0
20
40
60
80
100
Range (km)
M
edianJ/S(dBwrt-1
60dB
W)
1000 Watt EIRP Jammer at 100 feet AGL, Receiver at 5 feet AGL
free space
Hata Urban
Hata Suburban
Hata Rural Quasi-Open
Hata Rural Open
Nominal Unaided P-codeReceiver J/S Threshold
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Part II: Jamming & Spoofing Mitigations for Military and CivilGPS/GNSS Jamming has long been of concern to military users and recently, has
also become a concern for civil users. This webinar first provides anoverview of classic military mitigations against interference including
robust front end design, adaptive arrays, inertially aided tracking, andother techniques. The current civil jamming environment is thendescribed and the prospects for applying classic techniques to civilusers are examined. An overview of spoofing and jamming detectionmethods is also included and it is argued that civil user equipmentsshould maintain situational awareness.
Wednesday, March 6, 2013
Registration at:http://www.microwavejournal.com/Webinar_6mar13
Sponsored By:
http://www.microwavejournal.com/Webinar_6mar13http://www.microwavejournal.com/Webinar_6mar13http://www.microwavejournal.com/Webinar_6mar13