Post on 30-Jun-2020
transcript
Slide 1 2015 IES
Jade Morton, Yu Jiao, Steve Taylor Electrical and Computer Engineering Department
Colorado State University
High-latitude & Equatorial Ionospheric Scintillation Based on
An Event-Driven Multi-GNSS Data Collection System
Slide 2 2015 IES
Outline
1. Why Event-Driven Multi-GNSS ? 1. Sample High-Lat & Equatorial Results
Slide 3 2015 IES
Amplitude Fading: Receiver Processing Artifacts
50 52 54 56 58 600
5
10
15
20
25
30
35
40
45
Time(sec)
C/N 0(d
B-Hz
)
Tracked C/N0
Simulated C/N0
Slide 4 2015 IES
GPS Carrier Phase During Deep Fading: An Example
-1.5
-1
-0.5
0
0.5
-40
-30
-20
-10
Time (ms)
Sign
al In
tens
ity
(dB
) C
arrie
r Pha
se
(Cyc
les)
20 40 60 80
-10 -20 -30 -40
0.5
0
0.5
1
1.5
CTL 10ms FPF 10ms FPF 40ms *
Slide 5 2015 IES
Issues: Conventional ISM Receivers
High quality, raw GNSS signals are needed for space weather studies and
robust GNSS receiver development
1. Accuracy (Iono + other) X h(t) = Observed Effects
Iono effects ≠ Observed Effects
2. Availability Receivers cease to function during strong space weather events Data are not available when needed most!
3. Repeatability Receiver processing is irreversible Ionosphere effects are wiped out during processing
Slide 6 2015 IES
Event Driven Raw Data Collection System
Commercial ISM Receiver
RF Front End 1
RF Front End 2
RF Front End N
Space Weather Events
Data Collection and Control Server
Space Weather Event Monitoring & Trigger
Software
Circular Buffer
Circular Buffer
Circular Buffer
Dat
aS
tora
ge
VPN
Data Center at Home Institution
Inte
rnet
Specially designed signal tracking algorithms
Scientific analysis Algorithm development
Slide 7 2015 IES
Event-Driven Multi-Constellation GNSS Network
Ethiopia
Slide 8 2015 IES
Equatorial Scintillation Spatial Distribution
Slide 9 2015 IES
Diurnal Patterns
0 6 12 18 240
0.1
0.2
0.3
0.4
0.5
Hours after sunset
Slide 10 2015 IES
Solar Cycle Dependence: High vs. Low Lat
Slide 11 2015 IES
0
100
-800
0
800
P
erce
nt
B F
ield
Var
iatio
n (n
T)
H
D
Z
Percent of SV Affected
Geomagnetic Disturbance Impact on High Latitude
0 2 4 6 8 10 12 14 16 18 20 22 24Time (Hours)
HAARP, AK 7/15/2012
0 500 1000 1500 2000
0.4
0.6
0.8
1
(nT)
Prob
abili
ty o
f maxσ φ
>30o
maxH - minHmaxD - minDmaxZ - minZ
(H2+D2+Z2)1/2peak-to-peak
0 150 300 450
0.4
0.6
0.8
1
(nT)
σH
σD
σZ
(σH2+σ
D2+σ
Z2)1/2
Slide 12 2015 IES
Frequency Diversity: Selective Fading
Slide 13 2015 IES
Multi-Frequency Deep Fading
Carrier Phaser Reversal During Deep Fading
Slide 14 2015 IES
Adaptive Joint Time-Frequency Analysis
Slide 15 2015 IES
Irregularity Dynamics Sensing Using GNSS Array
Slide 16 2015 IES
Array Processing: HAARP (Gakona, Alaska) Lat: 62.39o, Lon: 145.15oW
NorthHF Heating Array
Operation Center
Ant 1
Ant 2
Ant 3Science Pad 3
Ant 4
1km
3km
¼ km
Slide 17 2015 IES
Commercial ISM Receiver
SDR 1GPS L1/GAL E1
SDR 3GAL E5b/BDS B2
Data Collection and Control Server
Space Weather Event Monitoring & Trigger
Software
VPN
Internet
SDR 6GPS L2C
SDR 7BDS B1
SDR 2GPS L5/GAL E5a
SDR 4GLO L1
SDR 5GLO L2
Circular Buffer
RAID Storage
OCXO
Gakona
Poker Flat(65.1oN, 147.5oW)
(62.3oN, 145.3oW)
90% Auroral oval boundary
New Alaska Deployment Poker Flat Advanced Modular Incoherent Scatter Radar (AMISR)
Multi-Constellation GNSS Receiver Array
Ant 1
Ant 2
Ant 3
Slide 18 2015 IES
Plasma Structure Dynamics Monitoring
Slide 19 2015 IES
0 5 10 15 20 25 30 35 40 450
250
500
750
1000
1250
1500
1750
σφ (degrees)
Ava
ilabl
e S
uper
DA
RN
Dat
a P
oint
sAvailable SuperDARN Data Points vs. σ
φ
Scintillation
Low/no scintillation
Comparison with SuperDARN
Slide 20 2015 IES
Novel GNSS Receiver Algorithms
• Adaptive Filtering
• Adaptive Inter-Channel Frequency Aiding
• Multi-Constellation Vector Processing
• Fixed Position Feedback
• Adaptive Drift Velocity Feedback
Slide 21 2015 IES
Conclusions
• High quality GNSS data is needed for – Continuous, accurate interpretation of ionosphere processes – Robust GNSS receivers development
• Successful data collection system yielding both known results as well as new observations – Adaptive processing is needed – Computation cost need to be improved
Slide 22 2015 IES
Acknowledgements
• Funding support from: – AFOSR, AFRL, NSF, DAGSI, Miami Univ., Colorado State Univ. – Industrial support: Rockwell Collins, Honeywell, Northrop Grumman, Mitre
Co., Lockheed Martin, Topcon, Symmetricom, Septentrio, Novatel, John Deere. • Collaborators:
– Ohio University, AFIT, University of Alaska Fairbanks, Singapore Nanyang Technical University, Hong Kong Polytechnic University, Boston College, Stanford University, University of Colorado Boulder, University of Hawaii
– Arecibo Observatory, Jicamarca Radio Observatory, Poker Flat Rocket Range and HAARP, Sondrestrom Observatory.
• Students/Post-docs: – Harrison Bourne, Steve Taylor, Jun Wang, Joy Jiao, Dongyang Xu, Brian
Breitsch, Jack Hall, Brian Jamieson, Mark Carroll, Robert Cole, Hang Yin, Richard Marcus, Mellissa Simms, Fan Zhang, Kyle Wyan, Kyle Kauffman, Xiaolei Mao, Ruihui Di, Fei Niu, Ryan Wolfarth, Praveen Vikram, Dan Charney, Greg Distler, Greg Newstadt, Adam Hill, Matt Cosgrove, Nick Matteo, Aaron Pittenger, Priyanka Chandrasekaran, Cheng Wang, Xiaoli Liu, Senlin Peng, Nazalie Kassanbian, Lei Zhang, Xin Chen, Hu Wang, Hong Wu, Yanhong Kou.
Slide 23 2015 IES
Common Volume LEO and Ground Observations
Slide 24 2015 IES
Multi-Frequency Fading Analysis
Slide 25 2015 IES
Fading Overlap: Ascension Island
Very small percentage
Fading band L1 L2C L5
L1 only 95.3% / /
L2C only / 82.9% /
L5 only / / 80.7%
Concurrent L1 and L2C 3.0% 1.3% /
Concurrent L1 and L5 1.4% / 0.7%
Concurrent L2C and L5 / 15.7% 18.5%
Concurrent L1, L2C and L5 0.2% 0.1% 0.1%
Fading Number
L1 1,791
L2C 4,591
L5 1,584
Total 7,966
Threshold of detrended signal intensity: -15dB
Concurrent L1, L2C and L5 0.2% 0.1% 0.1%
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