Satellite Positioning

Satellite Positioning

Matthieu Lonchay

Performances under Ionospheric Scintillations

Geomatics Unit

Thesis Committee

June 11, 2013

Geomatics Unit, ULg

University of Liège, Belgium

F.R.S.-FNRS, Belgium

Introduction

Research

Perspectives

Objectives

Conclusions

The Ionosphere is Ionized by Solar Radiation

UV

X-RaysMeV protons

CME’s

Solar Winds

Solar Flares

Introduction – Ionosphere

�� 1 � 40.3

� ��

�

�

� � � 40.3 � � ��

�

�� 40.3

� ��

GNSS Signals are refracted by the Ionosphere


�� 1 � 40.3

� ��

�

��

� � � 40.3 � � ��

�

�� 40.3

� ��

��

��

��

��

GNSS Signals are refracted by the Ionosphere


��

Ionospheric Electron Density

Irregularities

Spatial Variation of the

Refraction Index

Signal Losses

Signal Diffraction

Constructive and Destructive

Signal Interferences

~

GNSS Signals are diffracted by the Ionosphere


Ionospheric Electron Density

Diffraction Pattern

Received Signal Intensity

�!

�!

"

GNSS Signals are diffracted by the Ionosphere


UV

X-Rays

MeV protons

CME’s

Solar Winds

Solar Flares #$� %��&� �$�'$"'(� )&�"�

Ionospheric Electron Density Irregularities are

involved by Geomagnetic Storms


Geomagnetic Storms can be detected

by global Geomagnetic Indices

Halloween Storm

300/03 27-Oct-2003

2

4

6

8

KP

0

100

200

300

400

AP

-500

-400

-300

-200

-100

0

100

DST [nT]

00h 03h 06h 09h 12h 15h 18h 21h 24h


Geomagnetic Storms can be detected

by global Geomagnetic Indices

Halloween Storm

302/03 29-Oct-2003

2

4

6

8

KP

0

100

200

300

400

AP

-500

-400

-300

-200

-100

0

100

DST [nT]

00h 03h 06h 09h 12h 15h 18h 21h 24h


Ionospheric Electron Density Irregularities involve

GNSS Signal Phase and Amplitude fluctuations

Brussels - Simulation

001/11 01-Jan-2011

N

E

S

W

0°

30°

60°

15

30

45

60

75

Elevation [°]

-15

0

15

WLNL [m]

40

45

50

S1C [dB Hz]

06h 09h 12h 15h


Ionospheric Scintillation Effects on GNSS Signals

are Monitored by Scintillation GNSS Receivers

Low Data Rate (≈ 0.01 - 1 Hz)

Positioning

RINEX Files

Classic Observables

- C1C- L1C- D1C- S1C- …

High Data Rate (≈ 50-100 Hz)

ISMR Files

Space Weather

Specific Observables

- S4- Phi60- …

*+ � �� , � ��

-. � /� , / �

Ionospheric Scintillation Monitoring Receiver - ISMR


Ionospheric Scintillations exhibit

Spatial and Temporal Characteristics

FrequentInfrequent

Operating Frequencies

Geographic Locations

Local Time

Season

Magnetic Activity

Solar Activity


Ionospheric Scintillations exhibit

Spatial and Temporal Characteristics

FrequentInfrequent

Large Scale Irregularities

≈ 100 km

Small Scale Irregularities

≈ 1 – 100 m

Background Plasma Drift Speed

≈ 50-150 ms-1

Duration

≈ minutes/hours

Spatiotemporal Variations of

Scintillations Intensity


Satellite Positioning is based on Multilateration

�� t � 1�� 2 �� 2 ��,4,5� 2 c ∆"� , ∆"� 2 8�,4,5� 2 9�,4,5�

:�� t � 1�� 2 �� , ��,4,;� 2 c ∆"� , ∆"� 2 <4��,4� 2 8�,4,;� 2 9�,4,;�

��,4� � 40.3 � ��

sTEC

1�� =>� , >�?�2=@� , @�?�2=�� , ��?�

9�,4,5�

��,4�

9�,4,;��

�

Introduction – Positioning

The Standard Point Positioning is an elementary SF Technique

�� t � 1�� 2 �� 2 ��,4,5� 2 c ∆"� , ∆"� 2 8�,4,5� 2 9�,4,5�

Pseudorange (code) measurements

Single Point Single Epoch (SPSE) Technique

Atmospheric Models (Ionosphere and Troposphere)

Broadcast Ephemeris

1�� =>� , >�?�2=@� , @�?�2=�� , ��?�

Real-Time / Post-Processing

Static / Kinematic

�

�

Least Square Adjustement (LSA) to resolve unknowns

Single Frequency


The Standard Point Positioning is an elementary SF Technique

Brussels

001/12 01-Jan-2012

0

5

10

15

Error [m]

-10

-5

0

5

10

Error [m]

North

East

Up

3D Error

00h 03h 06h 09h 12h 15h 18h 21h 24h


�� t � 1�� 2 �� 2 ��,4,5� 2 c ∆"� , ∆"� 2 8�,4,5� 2 9�,4,5�

�

�

:�� t � 1�� 2 �� , ��,4,;� 2 c ∆"� , ∆"� 2 <4��,4� 2 8�,4,;� 2 9�,4,;�

Pseudorange (code) and Carrier-Phase measurements

Dual Frequency

Strategies against atmospheric effects

Precise Products: Ephemeris / Code-Phase Delays / Antenna

Real-Time / Post-Processing

Static / Kinematic

Sequential Least Squares Adjustment (Filter)

Ambiguity Resolution Process

The Precise Point Positioning is an advanced DF Technique


�� t � 1�� 2 �� 2 ��,4,5� 2 c ∆"� , ∆"� 2 8�,4,5� 2 9�,4,5�

�

�

:�� t � 1�� 2 �� , ��,4,;� 2 c ∆"� , ∆"� 2 <4��,4� 2 8�,4,;� 2 9�,4,;�

��,�A� t � 1�� 2 �� 2 c ∆"� , ∆"� 2 8�,�A,5� 2 9�,�A,5�

:�,�A� t � 1�� 2 �� 2 c ∆"� , ∆"� 2 <�A��,�A� 2 8�,�A,;� 2 9�,�A,;�

Mathematical Model: Ionosphere-Free + Precise Products

Solution: Sequential Least Square Adjustment (Filter)

Stochastic Model




Brussels

001/12 01-Jan-2012

0

0.5

1

1.5

2

2.5

3

Error [m]

-2

-1

0

1

2

3

Error [m]

North

East

Up

3D Error

00h 03h 06h 09h 12h 15h 18h 21h 24h


The Precise Point Positioning is highly sensitive to

Ionospheric Scintillations Effects

Brussels

069/12 09-Mar-2012

0

5

10

15

20

Error [m]

-15

-10

-5

0

5

10

15

Error [m]

North

East

Up

3D Error

00h 03h 06h 09h 12h 15h 18h 21h 24h


Brussels

069/12 09-Mar-2012

2

4

6

8

KP

-15

-10

-5

0

5

10

15

Error [m]

North

East

Up

00h 03h 06h 09h 12h 15h 18h 21h 24h


The Precise Point Positioning is highly sensitive to

Ionospheric Scintillations Effects

Introduction

Research

Perspectives

Objectives

Conclusions

Objectives

The Project aims to develop new Strategies to mitigate the

impact of Ionospheric Scintillations on Satellite Positioning

Softwares

Analysis

Stochasticity

Geometry

Preprocessing

Development of Scintillation Analysis Tools

Adaptation of existing softwares

Objectives



Softwares

Analysis

Stochasticity

Geometry

Preprocessing

Statistical Analysis of Scintillation Effects

Symptomatic Analysis of Scintillation Effects

Objectives



Softwares

Analysis

Stochasticity

Geometry

Preprocessing

Stochastic Model Improvement

Spatial/Empirical Approach

Correlations Assessment between Observables

Correlations Assessment between Satellites

Validation on SPP and PPP

Validation on different Scintillations Types

- Equatorial and Polar Scintillations

- Weak/Moderate/Intense Scintillations

Objectives



Softwares

Analysis

Stochasticity

Geometry

Preprocessing

Analysis of Geometric Effects of Scintillations

Objectives



Softwares

Analysis

Stochasticity

Geometry

Preprocessing Validation of a Cycle Slips Treatment Method

Introduction

Research

Perspectives

Objectives

Conclusions

Introduction

Research

Perspectives

Objectives

Conclusions Softwares

Analysis

Stochasticity

Geometry

Preprocessing

ESA/gAGE (UPC)

GNSS Data Processing Tool

GNSS Data Analysis Tool

Support

Multipurpose

ScientificProfessionalEducational

gLAB is a SPP and PPP Software for Scientific Purposes

Research – Softwares

Data Downloading

SPP and PPP Processing – Parameters?

Data Files Reading

Specific Treatments

Results Visualisations

Graphic Tools: IPP Maps and Skyplots

gLAB can be coupled with a Matlab Environment Programming

Research – Softwares

287/12 13-Oct-2012

W

00.20.40.60.8

1

Phi60 [rad]

1530456075

Elevation [°]

-15

0

15WLNL [m]

40

45

50S1C [dB Hz]

06h 09h 12h 15h

Introduction

Research

Perspectives

Objectives


Analysis

Stochasticity

Geometry

Preprocessing

15 ° W

0 ° 15° E

30° E

45° E

30 ° N

45 ° N

60 ° N

75 ° N

BRON

CYPR

LERW

NOTT

TRON

DOUR

ROME

BATH

NCTL

± 2010

± 2011

± 2012

Ionospheric Scintillation Monitoring Receivers (ISMR) Network

Septentrio and Novatel ISMR

RINEX 30”

ISMR 60”

Results – Analysis

1940 1950 1960 1970 1980 1990 2000 2010

Year

0

100

200

300

400International Sunspot Number

0

100

200

300 Daily Mean AP Index


Severe Geomagnetic Storms occur under High Solar Activity

2012 2013

Year

0

100

200

300

400

International Sunspot Number

0

100

200


Daily Max AP Index


Brønnøysund

Geomagnetic Storms still occur under Moderate Solar Activity

2012 2013

Year

0

1

2

3

4

5

6

Daily Max S4

Daily Max Phi60 [rad]

0

100

200


Daily Max AP Index


Brønnøysund

Ionospheric Scintillations occur under Moderate Solar Activity

The Analysis Strategy is based on the Selection of 5 typical Days

KP Index

2468

28-Sep-2012

272/12

2468

15-Dec-2012

350/12

2468

09-Mai-2012

130/12

2468

13-Oct-2012

287/12

2468

03-Jun-2012

155/12

00h 03h 06h 09h 12h 15h 18h 21h 24h



Single Station

Approach

Occurrence: Measurements and Epochs

The Analysis Strategy is based on specific Criteria

Multi Station

ApproachPositioning: SPP and PPP

Geometry: Satellite Number and Dilution of Precision

Spatial Characteristics

Cycle Slips

Noise Measurement

Low/High Magnetic Activity

Medium/High

Latitude


Single Station

Approach



Multi Station




Cycle Slips

Noise Measurement


Medium/High

Latitude


Ionospheric Scintillations affect

a very Small Portion of the Measurements

Brønnøysund

Year 2012

97%

3%

S4

< 0.25

> 0.25

92%

7%< 1%

[ 0.25 - 0.4 [

[ 0.4 - 0.55 [

[ 0.55 - ... [

100%

< 1%

Phi60

65%

19%

16%

Brønnøysund

Year 2012

52%48%

S4

< 0.25

> 0.25

73%

22%

4%

[ 0.25 - 0.4 [

[ 0.4 - 0.55 [

[ 0.55 - ... [

97%

3%

Phi60

58%

21%

21%



a Significant Portion of the Observation Epochs

Brønnøysund

350/12 15-Dec-2012

55%

45%

S4

< 0.25

> 0.25

75%

21%

4%

[ 0.25 - 0.4 [

[ 0.4 - 0.55 [

[ 0.55 - ... [

100%

< 1%

Phi60

50% 50%




Brønnøysund

350/12 15-Dec-2012

0123456789

KP

00h 03h 06h 09h 12h 15h 18h 21h 24h

0.00

0.20

0.40

0.60

0.80

1.00

S4

Mean S4 Max S4

0.00

0.20

0.40

0.60

0.80

1.00

Phi60

Mean Phi60 Max Phi60




Brønnøysund

287/12 13-Oct-2012

51%49%

S4

< 0.25

> 0.25

72%

23%

5%

[ 0.25 - 0.4 [

[ 0.4 - 0.55 [

[ 0.55 - ... [

73%

27%

Phi60

68%

16%

16%

55%

45%

100%

< 1%

50% 50%

75%

21%

4%




Brønnøysund

287/12 13-Oct-2012

0123456789

KP

00h 03h 06h 09h 12h 15h 18h 21h 24h

0.00

0.20

0.40

0.60

0.80

1.00

S4

Mean S4 Max S4

0.00

0.20

0.40

0.60

0.80

1.00

Phi60

Mean Phi60 Max Phi60





Single Station

Approach



Multi Station




Cycle Slips

Noise Measurement


Medium/High

Latitude

SPP and PPP Techniques are affected differently

by Ionospheric Scintillations Effects

Brønnøysund

350/12 15-Dec-2012

2

4

6

8

KP

-10

-5

0

5

10

SPP [m]

-2

-1

0

1

2

PPP [m]

North

East

Up

00h 03h 06h 09h 12h 15h 18h 21h 24h


Brønnøysund

350/12 15-Dec-2012

-5 -4 -3 -2 -1 0 1 2 3 4 5

East [m]

SPP

-5

-4

-3

-2

-1

0

1

2

3

4

5

North [m]

-5 -4 -3 -2 -1 0 1 2 3 4 5

East [m]

PPP




Brønnøysund

287/12 13-Oct-2012

2

4

6

8

KP

-10

-5

0

5

10

SPP [m]

-15

-10

-5

0

5

10

15

PPP [m]

North

East

Up

00h 03h 06h 09h 12h 15h 18h 21h 24h


- 30 %

+ 380 %



- 30 % + 380 %

Brønnøysund

287/12 13-Oct-2012

-5 -4 -3 -2 -1 0 1 2 3 4 5

East [m]

SPP

-5

-4

-3

-2

-1

0

1

2

3

4

5

North [m]

-5 -4 -3 -2 -1 0 1 2 3 4 5

East [m]

PPP





Single Station

Approach



Multi Station




Cycle Slips

Noise Measurement


Medium/High

Latitude


Brønnøysund

350/12 15-Dec-2012

2

4

6

8

KP

00h 03h 06h 09h 12h 15h 18h 21h 24h

2

4

6

8

10

12

Satellites

2468

101214

PDOP

< 0.25

[ 0.25 – 0.4 [

[ 0.4 – 0.55 [

> 0.55

Ionospheric Scintillations Decrease the Satellite Geometry


Brønnøysund

287/12 13-Oct-2012

2

4

6

8

KP

00h 03h 06h 09h 12h 15h 18h 21h 24h

2

4

6

8

10

12

Satellites

< 0.25

[ 0.25 – 0.4 [

[ 0.4 – 0.55 [

> 0.55

Ionospheric Scintillations Decrease the Satellite Geometry

Brønnøysund

287/12 13-Oct-2012

2

4

6

8

KP

00h 03h 06h 09h 12h 15h 18h 21h 24h

2

4

6

8

10

12

Satellites

2468

101214

PDOP


+ 11%

+ 28%+ 25%

< 0.25

[ 0.25 – 0.4 [

[ 0.4 – 0.55 [

> 0.55

Ionospheric Scintillations Increase the Dilution of Precision


Single Station

Approach



Multi Station




Cycle Slips

Noise Measurement


Medium/High

Latitude


High Phi60 values are frequently observed at High Latitudes


Brønnøysund

287/12 13-Oct-2012

0123456789

KP

00h 03h 06h 09h 12h 15h 18h 21h 24h

0.00

0.20

0.40

0.60

0.80

1.00

Phi60

Ionospheric Scintillations: a Spatio-Temporal Phenomenon


< 0.25

[ 0.25 – 0.4 [

[ 0.4 – 0.55 [

> 0.55



Brønnøysund

130/12 09-Mai-2012

0123456789

KP

00h 03h 06h 09h 12h 15h 18h 21h 24h

0.00

0.20

0.40

0.60

0.80

1.00

Phi60



< 0.25

[ 0.25 – 0.4 [

[ 0.4 – 0.55 [

> 0.55



Single Station

Approach



Multi Station




Cycle Slips

Noise Measurement


Medium/High

Latitude


Brønnøysund

350/12 15-Dec-2012

2

4

6

8

KP

00h 03h 06h 09h 12h 15h 18h 21h 24h

2

4

6

8

10

12

Satellites

2

4

6

8

10

12

Cycle Slips

< 0.25

[ 0.25 – 0.4 [

[ 0.4 – 0.55 [

> 0.55

Ionospheric Scintillations involve Cycle Slips


Brønnøysund

287/12 13-Oct-2012

2

4

6

8

KP

00h 03h 06h 09h 12h 15h 18h 21h 24h

2

4

6

8

10

12

Satellites

2

4

6

8

10

12

Cycle Slips6/10 4/6 + 186%

< 0.25

[ 0.25 – 0.4 [

[ 0.4 – 0.55 [

> 0.55

Ionospheric Scintillations involve Cycle Slips


Single Station

Approach



Multi Station




Cycle Slips

Noise Measurement


Medium/High

Latitude


Brønnøysund

287/12 13-Oct-2012

N

E

S

W

0°

30°

60°

00.20.40.60.8

1

Phi60 [rad]

1530456075

Elevation [°]

-15

0

15WLNL [m]

40

45

50S1C [dB Hz]

06h 09h 12h 15h

High Phi60 values do not seem to be correlated

with Noise Measurement

Analysis: Single Station Approach Summarize


Occurence

Positions

Geometry

Cycle Slips

Locations

Noise

Quiet Intense

Phi60 / S4

SPP/PPP

Main Scintillations Trouble

Cycle Slips Repair

Spatial Distribution



Single Station

Approach



Multi Station




Cycle Slips

Noise Measurement


Medium/High

Latitude

15 ° W

0 ° 15° E

30° E

45° E

30 ° N

45 ° N

60 ° N

75 ° N

BRON

CYPR

LERW

NOTT

TRON

DOUR

ROME

BATH

NCTL

± 2010

± 2011

± 2012

Ionospheric Scintillation Monitoring Receivers (ISMR) Network

Septentrio and Novatel ISMR

RINEX 30”

ISMR 60”



Brønnøysund

287/12 13-Oct-2012

51%49%

S4

< 0.25

> 0.25

72%

23%

5%

[ 0.25 - 0.4 [

[ 0.4 - 0.55 [

[ 0.55 - ... [

73%

27%

Phi60

68%

16%

16%

The Occurrence of Ionospheric Scintillations

clearly depends on the Geographic Latitude


Lerwick

287/12 13-Oct-2012

79%

21%

S4

< 0.25

> 0.25

87%

12%< 1%

98%

2%

Phi60

90%

7%3%

[ 0.25 - 0.4 [

[ 0.4 - 0.55 [

[ 0.55 - ... [




Cyprus

287/12 13-Oct-2012

95%

5%

S4

< 0.25

> 0.25

99%

1%

99%

< 1%

Phi60

25%

42%

33%

[ 0.25 - 0.4 [

[ 0.4 - 0.55 [

[ 0.55 - ... [




Brønnøysund Lerwick Cyprus

287/12 13-Oct-2012

0123456789

KP

00h 03h 06h 09h 12h 15h 18h 21h 24h

0.00

0.20

0.40

0.60

0.80

1.00

Max S4

0.00

0.20

0.40

0.60

0.80

1.00

Max Phi60

Brønnøysund

Lerwick

Cyprus





287/12 13-Oct-2012

0123456789

KP

00h 03h 06h 09h 12h 15h 18h 21h 24h

0

2

4

6

8

10

SPP

0.00

2.00

4.00

6.00

8.00

10.00

PPP

Brønnøysund

Lerwick

Cyprus


by Ionospheric Scintillations according to Geographic Latitude


Satellite Geometry Quality is affected differently



287/12 13-Oct-2012

00h 03h 06h 09h 12h 15h 18h 21h 24h

2468

1012

Brønnøysund

2468

1012

Lerwick

2468

1012

Cyprus

< 0.25

[ 0.25 – 0.4 [

[ 0.4 – 0.55 [

> 0.55



287/12 13-Oct-2012

0123456789

KP

00h 03h 06h 09h 12h 15h 18h 21h 24h

0

5

10

15

20

25

30

PDOP

Brønnøysund

Lerwick

Cyprus

Satellite Geometry Quality is affected differently



Ionospheric Scintillations concern only High Latitude

Ionopheric Pierce Point

< 0.25

[ 0.25 – 0.4 [

[ 0.4 – 0.55 [

> 0.55

Analysis: Multi Station Approach Summarize


Occurence

Positions

Geometry

Cycle Slips

Locations

Noise

Brønnøysund

Phi60 / S4

SPP/PPP

Main Scintillations Trouble


Cyprus Lerwick

-

-

Introduction

Research

Perspectives

Objectives


Analysis

Stochasticity

Geometry

Preprocessing

Results – Stochasticity

Satellite Positioning is Resolving a Problem with

several unknowns and equations

Mathematic Model

Stochastic Model

Resolution Process




Mathematic Model

Stochastic Model

Resolution Process

��,�A� t � 1�� 2 �� 2 … :�,�A� t � 1�� 2 �� 2 …��,�A� t � 1�� 2 �� 2 … :�,�A� t � 1�� 2 �� 2 ……




Mathematic Model

Stochastic Model

Resolution ProcessC*% %�DE�"F&�"G$�F$� H'�"&�…




Mathematic Model

Stochastic Model

Resolution Process

=Σ

221

22221

11221

...

..........

..

..

nnn

n

n

σσσ

σσσσσσ




Mathematic Model

Stochastic Model

Resolution Process

=Σ

1...00

..........

0..10

0..01




Mathematic Model

Stochastic Model

Resolution Process

=Σ

2

22

21

...00

..........

0..0

0..0

nσ

σσ




Mathematic Model

Stochastic Model

Resolution Process

=Σ

221

22221

11221

...

..........

..

..

nnn

n

n

σσσ

σσσσσσ

Spatial Approach

Empirical Approach

“Everything is related to everything else, but near things are more related than distant things.”


First Law of Geography…

Waldo Tobler


2)(

))((

vv

vvvvw

w

NI

ii

jiijji

ijji −Σ−−ΣΣ

ΣΣ=

ijij d

w1=

ii CSv 1=

N

E

S

W

0°

30°

60°

1. Spatial Autocorrelation Test

The « Spatial Strategy relies on the fact there exists some

Spatial Autocorrelation in Scintillations Observations


0h 3h 6h 9h 12h-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

Time [h]

Moran's I

Simulated Scenario

N

E

S

W

0°

30°

60°





N

E

S

W

0°

30°

60°


2. Covariance Function

Description of the Spatial Covariance of a

random Variable process




30 ° W

20 ° W

10 ° W 0° 10° E

20° E

30° E

40° E

50 ° N

60 ° N

70 ° N

80 ° N

N

E

S

W

0°

30°

60°








30 ° W

20 ° W

10 ° W 0° 10° E

20° E

30° E

40° E

50 ° N

60 ° N

70 ° N

80 ° N

��

��

�I








United Kingdom - Ordnance Survey Network

10° W 5° W 0°

50° N

55° N

60° N

United Kingdom – Ordnance Survey Network CHAIN – Canadian High Artic Ionospheric Network

70 ° N

75 ° N

80 ° N

120 ° W

115 ° W

110 ° W 105 ° W

100 ° W 95° W 90° W 85° W 80° W

75° W 70

° W 65

° W

60° W

60 ° N

65 ° N

3. RNX vs. ISMR

ISMR

RNX

Spatial

Density

Variable?

Time Correlation?

Multi-receiver?

Mapping Function?

Scintillation Level?

Time Sampling?

Polar / Equatorial Scintillations?


The « Empirical Strategy relies on Observations

whatever their Locations

2h 3h 4h 5h 6h 7h

Time [h]

=Σ

221

22221

11221

...

..........

..

..

nnn

n

n

t

σσσ

σσσσσσ

S4, σϕ ?

C/N0?

S1C?

C1C?

L1C?

D1C?

RoTEC ?

…

…

Tracking E ?

Introduction

Research

Perspectives

Objectives


Analysis

Stochasticity

Geometry

Preprocessing

Results – Geometry

PPOS DOP σσ ×=

Ionospheric Scintillation involve Satellite Signal Losses

Brønnøysund

287/12 13-Oct-2012

2

4

6

8

KP

00h 03h 06h 09h 12h 15h 18h 21h 24h

2

4

6

8

10

12

Satellites

2468

101214

PDOP


Ionospheric Scintillation increase the Dilution of Precision

< 0.25

[ 0.25 – 0.4 [

[ 0.4 – 0.55 [

> 0.55

9 satellites

9 satellites


The Dilution of Precision depends on the amount and

the Spatial Distribution of Tracked Satellites

N

E

S

W

0°

30°

60°

PDOP = 10.79

N

E

S

W

0°

30°

60°

PDOP = 2.58


A Conical Satellite Geometry drives the DOP to Infinite Values

PWAPAAx TT 1)( −−=22121)( PxPP

T

xQNAA σσσ === −−∑

PPOS DOP σσ ×=

44342414

34332313

24232212

14131211

:

qqqq

qqqq

qqqq

qqqq

Qx

11ˆ )( −− == AANQ Tx

−−−

−−−−−−

=

1sincoscossincos

............

1sincoscossincos

1sincoscossincos22222

11111

nnnnn

A

ηχηχη

ηχηχηηχηχη

Any linear dependence?



N

E

S

W

0°

30°

60°

PDOP = 10.79

N

E

S

W

0°

30°

60°

PDOP = 2.58


PDOP = 10.79 PDOP = 2.58

N

E

S

W

0°

30°

60°

N

E

S

W

0°

30°

60°



N

E

S

W

0°

30°

60°

PDOP = 4.39



PDOP = 152.05

N

E

S

W

0°

30°

60°

N

E

S

W

0°

30°

60°


Introduction

Research

Perspectives

Objectives


Analysis

Stochasticity

Geometry

Preprocessing

Results – Preprocessing

�

�:�� t � 1�� 2 �� , ��,4,;� 2 c ∆"� , ∆"� 2 <4��,4� 2 8�,4,;� 2 9�,4,;�

JK 2 � Testing Quantity

Detection Method

Correction Method

time

time

Cycle Slip Detection/Repair is a real need for

Precise Positioning Technique


1 2 3 4 5 Time [h]

-5

0

5

DF WLNL E1/E5a

[cycles]

-0.01

0

0.01

TF LCP E1/E5a/E5b

[m]

No CS

detected

Wrong

CS

detected

Giove-B TQs

99% Confidence Interval

The availability of Three Frequencies

makes the CS Detection more efficient

Validation of the Detection under IS

Development of a Correction Method

Adaptation to PPP


Observable Noise Assessment could help to define the

Stochastic Model (« Empirical Strategy »)

12 13 14 Time [h]

-1

0

1

Polynomial fitting

P-φ [m]

-2

-1

0

1

2

Time differencing

P-φ [m]

Introduction

Research

Perspectives

Objectives


Analysis

Stochasticity

Geometry

Preprocessing

Softwares

Analysis

Stochasticity

Geometry

Preprocessing

Symptomatic Analysis for a HL Station

Methodology

Equatorial Scintillations?

Conclusions

Softwares

Analysis

Stochasticity

Geometry

Preprocessing

Conclusions

Spatial / Empirical Strategies

Softwares

Analysis

Stochasticity

Geometry

Preprocessing

Illustration of Geometric Problems

Conclusions

Softwares

Analysis

Stochasticity

Geometry

Preprocessing

CS Detection Method

Validation of CS Detection for IS

Development of CS Repair Technique

Conclusions

Introduction

Research

Perspectives

Objectives

Conclusions

Perspectives

Introduction

Conclusions

State of the Art

Analysis GeometrySoftwares Stochasticity Preprocessing

Analysis

Solution

Validation

Analysis

Softwares

Preprocessing

Stochasticity

Geometry

100 10 20 40 15 15

- Versioning

- Python learning

- C learning

- Global Approach

- Global Design

- Adapations

- Stochastic Model

- Preprocessing

- Mathematic Model

- Weigthing Scheme

- Automatisation

- Stoch. Matlab Module

- Matlab routines

- Matlab mapping TB

- Matlab exe

- GIS software

Finalization

Jan14 Feb14 Mar14 Apr14 May14 Jun14 Jul14 Aug14 Sep14Oct13 Nov13 Dec13Jul13 Aug13 Sep13Jun13

FP

- Data Access

- Data Types

- Data Parsing

- Data Network

- Data Documentation

- Data Download

- Data Mapping

- Network Design

- SPP Process

- PPP Process

- SS Analysis

- MS Analysis

- Symptoms

Short Stay in Nottingham?

- Spatial Approach

ACS Study (Index)

ACS Study (covar.)

Corr. Observables

Index (RNX)

Spatial Interpolation

Covariance

Assesment

- Empirical Approach

Filter Construction

Tests

- Validation

gLAB

- Conical Theory

- M-GNSS

- Validation?

- CS Detection

TQ DF+TF

Filter Parameters

Validation DF+TF

- CS Repair

- Noise Assessment

Publication

Conference

Matthieu Lonchay

Performances under Ionospheric Scintillations

[email protected]

Geomatics Unit

Thesis Committee

June 11, 2013

Geomatics Unit, ULg

University of Liège, Belgium

F.R.S.-FNRS, Belgium

Satellite Positioning

Documents

Satellite Positioning