Dzana Halilovic 1 Robert Weber 1 dzanahalilovicgeotuwienacat 1 Technical University Vienna Department of Geodesy and Geoinformation Vienna Austria SGI 2019 Workshop Berlin Germany 26 27 September 2019 ID: 805049
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Slide1
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
Slide2Overview2
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
Slide33WP 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
Slide44High latitudes (above 55° north)
Central European latitudes (TUW region)
Azores and equatorial region
Motivation
SGI 2019 Workshop, Berlin, Germany, 26 - 27 September 2019
Slide55Network:
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
Slide66MSLM (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
Slide77Geometry-free linear combination (L4)
Methodology
: Linear
combination
SGI 2019 Workshop, Berlin, Germany, 26 - 27 September 2019
Slide88Methodology
: 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
Slide99Analysis
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
Slide10DoY
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
Slide11SGI 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
Slide12SGI 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
Slide1313Analysis:
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)
Slide1414Analysis:
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
Slide1515Analysis:
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)
Slide16modeltested
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
Slide1717Analysis:
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
Slide1818Analysis:
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
Slide1919Analysis:
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
Slide2020Conclusions
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
Slide21Thank you for
your attention!21