Slide 1

Ionosphere Effects on GNSS

Characterization

Joy Jiao, Jade Morton, Harrison Bourne, Brian Breitsch, Steve Taylor, Jun Wang, Dongyang Xu, Mark Carroll*, Hang Yin*

Colorado State University

Mitigation and Utilizationof

Slide 2

Introduction – Scintillation Phenomena

Wave front: uniform phase uniform amplitude

Incident wave Ionosphere

Ground

Diffraction/interference pattern

Wave emerging from below irregularities: non-uniform phase non-uniform amplitude

Amplitude fading ! S4 Random phase fluctuation ! !"

Slide 3

!"#

$%&'(

)*+,

%-.#%/0%%%1-2%30%%%4"5"/$64%%%%%%%%%%%%%%%%%%%789:;8<=;%>8?@;'%

!"#$%&'"$%()*+"

,-."/+0+12+&""

Slide 4

"! Characterization

Slide 5

Event Driven Raw IF Data Collection System Event Driven Raw IF Data Collection System

2AB':;A8C%%2A:D:%E@F?=G%*@GG<8=;%(=BG;:%

Slide 6

Event-Driven GNSS Data Collection Systems 345!367

375!367

85!364"9

85!363"9:5!364

75!36!"9

;5!36!"9665!36!"9

<56=635!36<

6!5!338"9>5!364

75!3669

Slide 7

Scintillation Occurrence Frequency - Diurnal

•! High latitude: night time •! Low latitude: 1-6 hours post local sunset

HAARP: LT = UTC – 5; Jicamarca: LT = UTC + 8; Ascension: LT = UTC2AB':;A8C%%H=F%H<@=%

Slide 8

Scin Occurrence vs. Seasons & Solar Activity

0

5

10

15

20

25

30

20

40

60

80

100 Gakona, Alaska Jicamarca, Peru

Mea

n ev

ent n

umbe

r

0 FA WI SP SU FA WI SP SU FA WI SP 2010 2011 2012 2014

SU SP SU FA WI 2013

Seas

onal

suns

pot n

umbe

r

SP: 3,4,5 SU: 6,7,8 FA: 9,10,11 WI: 12,1,2

2AB':;AC%%H=F%H<@=%

Slide 9

Geomagnetic Disturbance at High Latitude Gakona, AK 7/15/2012

2AB':;AC%%H=F%H<@=%

Slide 10

Equatorial Scintillation Spatial Distribution !3?33?33"@AB"<5635!36<""9"36?33?33"@AB"<5665!36<""""C'0+D'1$D",'E)DF

2AB':;A8C%%I@GJ%!@GG=??%K=;LF@;L%MB%#@+:?<:%N@88@O<@;%

Slide 11

Frequency Diversity: Selective Fading

E<P:%&2:9=;'8, 2AB':;AC%H=F%H<@=%

Slide 12

Triple-frequency Fading Overlap

G+&H"'I)EE"J+&0+D()*+

K)F1D*"L)DF M6"" M!B M7"

36%=;?F 50Q4R " "

3/!%=;?F " S/Q5R "

30%=;?F " " S$QTR

!=;9BGG:;A 36%@;'%3/! 4Q$R 6Q4R "

!=;9BGG:;A 36%@;'%30 6QUR " $QTR

!=;9BGG:;A% 3/!%@;'%30 " 60QTR 6SQ0R

!=;9BGG:;A 36V%3/!%@;'%30 $Q/R $Q6R $Q6R

K)F1D*"N%IL+& M6 6VT56 M!B UV056 M7 6V0SU

E=A@? TV5WW

A#&+'#$EF"$O"F+(&+DF+F"'1*D)E"1D(+D'1(H?"=67FP

B$D0%&&+D( M6Q"M!B")DF"M7 3R!S 3R6S 3R6S

Slide 13

"! Mitigation #! Optimization of conventional tracking (Mark Carroll)

#! Adaptive multi-frequency filtering (Hang Yin)

#! Multi-constellation vector tracking (Dongyang Xu)

Slide 14

Conventional Tracking Scheme

,D(+*&)T$D"TI+ A&)0U1D*"E$$J"L)DFV1F(#

W1*#"FHD)I10'""XJ#)'+"'01DTEE)T$DY

W1*#"D$1'+""X)IJE1(%F+"'01DTEE)T$DY

Slide 15

Adaptive Multi-Frequency (AMF) Carrier Tracking

2AB':;AC%*@;L%X<;%

Slide 16

Adaptive Multi-Frequency (AMF) Carrier Tracking

2AB':;AC%*@;L%X<;%

Slide 17

"! Utilization #! Ionospheric structure: TEC, TEC

gradient mapping

#! Plasma turbulence mapping

Slide 18

APT Time-Frequency Analysis

5 min from 2012/10/13 12:06:17 UTC

2AB':;AC%HB;%Y@;L%

Slide 19

GNSS vs. SuperDARN

Drift Velocity (m/s)

Km

Km

2AB':;AC%HB;%Y@;L%2AB':;AC%HB;%Y@;L%

Slide 20

Plasma Drift – Gakona, AK

2AB':;AC%HB;%Y@;L%

Slide 21

Summary of Future Plan

"!IB?Z)9=;8A:??@Z=;V%PB?Z)O@;'%1#22%[<??%O:%@%

P@\=G%:;@O?:G%]=G%<=;=8^_:G:%8^@9:%[:@A_:G%

8AB'<:8"

#! *<L_%`B@?<AF%G@[%>a%'@A@%<8%;::':'%A=%]@9<?<AF%A_:%8AB'F%

#! 799BG@A:%G:9:<D:G%^G=9:88<;L%@?L=G<A_P8%@G:%9G<Z9@?%A=%

P@<;A@<;%?=9J%=]%8<L;@?8%'BG<;L%8^@9:%[:@A_:G%:D:;A8%

@;'%A=%^G:8:GD:%AGB:%8^@9:%[:@A_:G%8<L;@ABG:%=;%1#22%

8<L;@?%^@G@P:A:G8%

Slide 22

Slide 23

Gakona, Alaska (HAARP)

Slide 24

Poker Flat Research Range, Alaska

Slide SCPNT 2014

Poker Flat Advanced Modular Incoherent Scatter Radar (AMISR)

Ant 1

790m

Multi-Constellation Multi-frequency GNSS Receiver Array

1.36km

Ant 1

Ant 2

Ant 3

Slide 25

Jicamarca Radio Observatory, Peru

Mobile unit

One multi-constellation multi-frequency IF collection system established. Additional array setup will be completed in 2015 funded by a NSF MRI

Slide 26

Arecibo Observatory, Puerto Rico

95 miles Culebra

Digisonde

Ramey

Arecibo ISR

Multi-Constellation GNSS Array. To be completed in 2015 funded by NSF MRI

Arecibo Observatory: Magnetometer, Optical Observatory, artificial HF heating

Slide 27

Available Data at Gakona, Alaska

Year 2010 2011 2012 2013 2014Month Day # % Day # % Day # % Day # % Day # %Jan.

Not available

31 100 8 25 22 70 0 0Feb. 28 100 20 68 28 100 25 89Mar. 23 74 15 49 31 100 31 100Apr. 29 96 0 0 30 100 30 100May 31 100 0 0 14 45 31 100June 30 100 22 74 30 100 22 73July 17 55 28 90 31 100

Not available

Aug. 6 19 21 68 27 87 31 100Sept. 28 90 0 0 30 100 30 100Oct. 15 48 6 19 31 100 31 100Nov. 29 97 14 47 30 100 25 83Dec. 31 100 19 60 8 26 20 64Total 109 71 249 68 219 60 323 88 139 77

Grand total in 2010 - 2014 1,038 73

Slide 28

Available Data at Jicamarca, Peru

Year 2012 2013 2014Month Day # % Day # % Day # %Jan.

Not available

30 95 0 0Feb. 28 100 7 25Mar. 30 97 24 77Apr. 29 95 24 80May 23 73 0 0June 13 42 0 0July 0 0 30 96Aug. 5 17

Not availableSept. 14 47Oct. 27 86Nov. 8 27 12 39Dec. 31 100 0 0Total 39 64 209 57 85 40

Grand total in 2012 - 2014 333 52

Slide 29

3. Duration ! 30 seconds

4. Two events detected within 5 minutes are counted as one

5. Scintillations experienced by multiple PRNs simultaneously are recorded separately

Scintillation Event Criteria

1. Elevation ! 30°

2. Alaska: S4 ! 0.15 OR !" ! 15°

Peru/Ascension:

S4 ! 0.2 OR !" ! 15°

Slide 30

Scintillation Event Frequency

$ 6$ /$4$ U$ 0$ W$ T$ S$ 2b%#=Q%@c:9A:'%7^%2b%#=Q%@c:9A:'%$ 6$ /$4$ U$ 0$ W$T$S$ 7^%

0 6 12 18 24 0

0.08

0.16

0.24

0.32

UTC LT

0 6 12 18

(b) Peru - Mar. 2013 (a) Alaska - Mar. 2013

Sci

ntill

atio

n oc

curr

ence

pr

obab

ility

24

0.08

0.16

0.24

0.32

15 21 3 9 15 19 1 7 13 19

Slide 31

Detrended SI Fading Overlap – Triple-frequency

Fading band Threshold L1

only L2C only

L5 only

Concurrent L1 and L2C

Concurrent L1 and L5

Concurrent L2C and L5

Concurrent L1, L2C and L5

L1 -10 dB 86.1% / / 7.5% 4.5% / 1.9% -15 dB 95.3% / / 3.0% 1.4% / 0.2% -20 dB 97.9% / / 1.4% 0.6% / 0 -25 dB 99.8% / / 0.2% 0 / 0

L2C -10 dB / 68.7% / 3.7% / 26.7% 0.9% -15 dB / 82.9% / 1.3% / 15.7% 0.1% -20 dB / 90.5% / 0.6% / 8.9% 0 -25 dB / 94.7% / 0.1% / 5.2% 0

L5 -10 dB / / 66.7% / 2.4% 29.8% 1.0% -15 dB / / 80.7% / 0.7% 18.5% 0.1% -20 dB / / 89.5% / 0.3% 10.2% 0 -25 dB / / 95.4% / 0 4.6% 0

Detrended SI Fading

PRN 24, 3/10/2013

Slide 32

Fading Duration Statistics

C/N0 FadingDetrended SI Fading

Slide 33

Drift Velocity Comparison 2012/10/09 06:02 - 06:20 UTC Alaska