GNSS-based Regional Ionosphere Modeling - PowerPoint Presentation

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GNSS-basedRegional Ionosphere Modeling

Dzana Halilovic1*, Robert Weber1* dzana.halilovic@geo.tuwien.ac.at1 Technical University Vienna, Department of Geodesy and Geoinformation, Vienna, Austria

SGI 2019 Workshop, Berlin, Germany, 26 – 27 September 2019

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Overview2

MotivationMethodologyModel overview (main characteristics)

Mapping

function

and

Linear combinationProcessing stepsAnalysisValidation sites, Output files, ModelsResults and statisticsConclusions and further work

SGI 2019 Workshop, Berlin, Germany, 26 - 27 September 2019

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WP Technical coordination

Norvegian Mapping Authority

NMA

NO

WP Participants

TU Wien (Technical University of Vienna)

TUVAT University of Porto

FCUP

PT

Space Research Centre, Polish Academy of Sciences

SRC/CBK

PL

Partnership in the GRC (Galileo Reference Centre) MS Consortium established by the GSA (European GNSS Agency)Aim of the WP:To study and analyze the performance of the NeQuick G ionospheric model in different latitudinal regionsComparison to the GPS Klobuchar modelEvaluation based on data from stations in three latitude regions

Motivation

SGI 2019 Workshop, Berlin, Germany, 26 - 27 September 2019

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High latitudes (above 55° north)

Central European latitudes (TUW region)

Azores and equatorial region

Motivation

SGI 2019 Workshop, Berlin, Germany, 26 - 27 September 2019

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Network:

35 permanent ground stations

Start DoY

:

274 (2018)

Grid size:

0.5°x 0.5°Coverage: +30° to +65° lat -15° to +45° lonTemporal resolution: 1h (25 maps in file)Observation type: geometry-free zero-difference code and carrier phaseSat.system: GPS+Galileo

Integrated

electron

density

:

Described by spherical harmonics (up to degree 6)Software:

Bernese v.5.2(Post-processing mode)Methodology: Model overviewStarting DoY with more Galileo data: 182 (2019)(Galileo contribution increased from 5 to 19 stations)  Quarter 3 to be analyzed after Sept 2019 SGI 2019 Workshop, Berlin, Germany, 26 - 27 September 2019

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MSLM (Modified Single-Layer Model)

All free electrons are concentrated in a shell of infinitesimal thickness at an effective height H (height of maximum electron density at the F2 peak and ranges from 350 km to 450 km.

 

Methodology

: Mapping

function

Single-layer model

SGI 2019 Workshop, Berlin, Germany, 26 - 27 September 2019

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Geometry-free linear combination (L4)

 

Methodology

: Linear

combination

SGI 2019 Workshop, Berlin, Germany, 26 - 27 September 2019

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Methodology

: Processing steps

1.

Preparation

Extraction

of:clock (*.clk)pole (*.erp) andprecise orbit (*.sp3)informationSite coordinate

extrapolation to

current

epoch

2. Preprocessing

Code observations screening and smoothingRinex files conversion  Bernese formatted fileFirst SPP solution:receiver clock synchronizationPhase observations preprocessingcycle slip detection and correctionoutlier detection3. ProcessingData residual screening (L3)Outlier identificationMarking identified outliers in observation filesPPP solution

final site

coordinate

estimation

Generate

ionosphere

model

(L4)

station

DCB

estimation

SGI 2019 Workshop, Berlin, Germany, 26 - 27 September 2019

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Analysis

Sites for validation:NICO ……………. 30°- 40° lat

AJAC

GRAS ……….. 40°- 50°

lat

LEOP

JOZ2 .....……….. 50°- 55° latused for DoY 274 (2018) – 90 (2019)Sites for validation:NICO ……………. 30°- 40° latAJACGRAS ……….. 40°- 50° latLEOP

WROC .....…….. 50°- 55° lat

used for

DoY

91 (2019) -

Output filesDaily VTEC maps for Central EuropeDaily VTEC difference maps for Central Europe w.r.t CODEDaily site specific range difference plotsDaily site specific residual IONO Slant Error plotsCompared models

TUW regionalNeQuick GalGPS KlobucharReference: CODESGI 2019 Workshop, Berlin, Germany, 26 - 27 September 2019

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DoY

046 (Q1/2019)Jan - Mar10Analysis: Results

VTEC maps

(TUW regional

model

)

SGI 2019 Workshop, Berlin, Germany, 26 - 27 September 2019DoY 135 (Q2/2019)Apr - Jun

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SGI 2019 Workshop, Berlin, Germany, 26 - 27 September 2019

11Analysis: Results

VTEC difference maps for Central Europe w.r.t CODE

DoY

046 (Q1/2019)

DoY

046 (Q1/2019)DoY 046 (Q1/2019)TUW regional w.r.t. CODEDifferences up to ~ 4 TECU for

this

day

NeQuick

Gal w.r.t. CODEDifferences up to ~ 8 TECU for this day

GPS Klobuchar w.r.t. CODEDifferences up to ~ 8 TECU for this day

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SGI 2019 Workshop, Berlin, Germany, 26 - 27 September 201912

Analysis: ResultsVTEC difference maps for Central Europe w.r.t CODE

DoY

135 (Q2/2019)

DoY

135 (Q2/2019)

DoY 135 (Q2/2019)TUW regional w.r.t. CODEDifferences up to ~ 3 TECU for

this

day

NeQuick

Gal w.r.t. CODEDifferences up to ~ 7 TECU for this day

GPS Klobuchar w.r.t. CODEDifferences up to ~ 10 TECU for this day

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Analysis:

ResultsDaily site specific range difference plots (I)L1+model w.r.t ionosphere-free linear combination (L3)SGI 2019 Workshop, Berlin, Germany, 26 - 27 September 2019

Mean

range

difference statistics (%)Model (%)<0.5m<1m<1.5mCODE

66,59

88,35

95,43

TUW reg.

62,9986,4394,31NeQuick G35,7462,6983,12

Klobuchar38,1664,3980,30DoY 046 (2019)

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Analysis:

ResultsDaily site specific range difference plots (II)

L1+model w.r.t ionosphere-free linear combination (L3)

SGI 2019 Workshop, Berlin, Germany, 26 - 27 September 2019

DoY

135 (2019)

Mean range difference statistics (%)

Model (%)

<0.5

m

<1m

<1.5mCODE62,6687,2695,78TUW reg.60,4786,77

95,59NeQuick G42,1275,7591,65Klobuchar32,0954,2269,08

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Analysis:

ResultsDaily site specific range difference plots - StatisticsSGI 2019 Workshop, Berlin, Germany, 26 - 27 September 2019

Mean

range

difference statistics (%)

Model

<0.5

m

STD

<1mSTD<1.5mSTD

CODE64,323,7188,291,7495,860,70TUW reg.62,303,4887,301,8195,430,80NeQuick G39,786,9869,557,1887,284,05Klobuchar29,865,8853,578,4669,289,00DoY 001-181 (2019)

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modeltested

valueobservationreference value16

Analysis: Results

Daily site specific residual IONO Slant Error plots (I)

Project defined specification

SGI 2019 Workshop, Berlin, Germany, 26 - 27 September 2019

STECREF - STECMOD2-freq. derived STECModel derived STEC

to all

visible

satellites

in all

elevation angles

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Analysis:

ResultsDaily site specific residual IONO Slant Error plots (II)SGI 2019 Workshop, Berlin, Germany, 26 - 27 September 2019DoY 046 (2019)

Model

Points outside

NeQuickG

spec. (%)CODE0,20TUW reg.0,26NeQuick G

0,54

STEC

REF

- STEC

MOD

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Analysis:

ResultsDaily site specific residual IONO Slant Error plots (III)SGI 2019 Workshop, Berlin, Germany, 26 - 27 September 2019DoY 135 (2019)

Model

Points outside

NeQuickG

spec. (%)CODE0,16TUW reg.0,14NeQuick G0,36

STEC

REF

- STEC

MOD

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Analysis:

ResultsDaily site specific residual IONO Slant Error plots - StatisticsSGI 2019 Workshop, Berlin, Germany, 26 - 27 September 2019

Mean

IONO

slant

error statisticsModelPoints outsideNeQuickG spec. (%)CODE0,19TUW reg.

0,19

NeQuick

G

0,59

DoY 001-181 (2019) Daily mean percentage of epochs outside the NeQuick G specification

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Conclusions

SGI 2019 Workshop, Berlin, Germany, 26 - 27 September 2019A notable agreement between the TUW regional model and the CODE model, used as a reference (differences up to 5 TECU)

A useful model to provide

ionospheric

information for single-frequency GNSS users in the European mid-latitude region

Further

workIncreased amount of multiGNSS observations in the existing processing included First results after September 2019 (for Q3)Analyze model performance including other satellite systemsCheck for stations from other networks (eg. EUREF) to improve model performance on map boundariesLooking for the next year’s Consortium contract with GSACheck if our results still match GSA KPIs for this work package

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Thank you for

your attention!21