Noise characteris,cs in Zenith Total Delay from ... · COST Action ES1206 - GNSS4SWEC, Final...
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COST Action ES1206 - GNSS4SWEC, Final Workshop, ESTEC, Netherlands, Feb 21-23, 2017 1/17 Noise characteris,cs in Zenith Total Delay from homogeneously reprocessed GPS ,me series Anna Klos 1 , Addisu Hunegnaw 2 , F. Norman Teferle 2 , Kibrom E. Abraha 2 , Furqan Ahmed 2# , and Janusz Bogusz 1 1 Military University of Technology, Faculty of Civil Engineering and Geodesy, Warsaw, Poland, [email protected] 2 University of Luxembourg, Geophysics Laboratory, Luxembourg, [email protected] #Current address: Center for Space Research, University of Texas at AusVn, USA.
Transcript of Noise characteris,cs in Zenith Total Delay from ... · COST Action ES1206 - GNSS4SWEC, Final...
COST Action ES1206 - GNSS4SWEC, Final Workshop, ESTEC, Netherlands, Feb 21-23, 2017
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Noisecharacteris,csinZenithTotalDelayfromhomogeneouslyreprocessedGPS,meseries
AnnaKlos1,AddisuHunegnaw2,F.NormanTeferle2,
KibromE.Abraha2,FurqanAhmed2#,andJanuszBogusz11MilitaryUniversityofTechnology,FacultyofCivilEngineeringandGeodesy,Warsaw,Poland,[email protected],GeophysicsLaboratory,Luxembourg,[email protected]#Currentaddress:CenterforSpaceResearch,UniversityofTexasatAusVn,USA.
COST Action ES1206 - GNSS4SWEC, Final Workshop, ESTEC, Netherlands, Feb 21-23, 2017
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Mo,va,on&workplan:1. homogenisaVonofZTDesVmates,2. divisionofTIGAstaVonsintovariousclimatezones,3. modellingtheZTDserieswithmathemaVcalmodel,4. esVmatesofapropernoisemodelforZTDseries.
Theaim:toshowhowmuchtheuncertaintyoftheZTDtrendsmaybeunderes,mated.
MOTIVATIONDATAMETHODOLOGYRESULTSCONCLUSIONS
KlosA.etal.:„NoisecharacterisVcsinZenithTotalDelay…”
COST Action ES1206 - GNSS4SWEC, Final Workshop, ESTEC, Netherlands, Feb 21-23, 2017
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Bri,shIslescon,nuousGNSSFacilityandUniversityofLuxembourgTideGaugeBenchmarkMonitoring(TIGA)AnalysisCenter(BLT):a) InternaVonalGNSSService(IGS)TideGaugeBenchmark
Monitoring(TIGA)analysiscentre,b) reprocessingofaglobalnetworkofGPSstaVonsfrom1995
to2015,c) morethan700staVons,d) hourlydata.
KlosA.etal.:„NoisecharacterisVcsinZenithTotalDelay…”
MOTIVATIONDATAMETHODOLOGYRESULTSCONCLUSIONS
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ReprocessingstrategyandmodelsappliedforBLTrepro2solu,on:a) BerneseGNSSSogwareBSW5.2(doubledifferencephaseand
codeobservaVons),b) VMF1andHydrostaVcaprioriandWettropospheremodel
fromVMF,c) troposphericgradients:ChenandHerringVltesVmaVonforN-S
andW-EdirecVons,d) esVmatesofZenithTotalDelay(ZTD)werecomputedevery
twohoursusingapiece-wiselinearfuncVonandgradientswereesVmatedat12hourintervals,
e) 3degreeselevaVoncut-offandthecosinequarVcdependentweighVng.
KlosA.etal.:„NoisecharacterisVcsinZenithTotalDelay…”
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Homogenisa,onofZTDseries:TheoffsetsreportedinGPSposiVonVmeserieswerevalidatedmanuallyinZTDdata.
Theonesappliedaretheonesfound/confirmedinZTDseries.
KlosA.etal.:„NoisecharacterisVcsinZenithTotalDelay…”
MOTIVATIONDATAMETHODOLOGYRESULTSCONCLUSIONS
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Divisionintoclimatezones:ClimatezonesfollowingtheKöppen-GeigerclassificaVon(Peeletal.,2007).Wefocusedonfiveclimatezonesforclassifyingtheworld'sclimatebasedontheannualandmonthlyaveragesoftemperatureandprecipitaVon.
KlosA.etal.:„NoisecharacterisVcsinZenithTotalDelay…”
Numberofsta,ons:Tropical:27Dry:13Warmtemperate:35ConVnental:22PolarandAlpine:23
MOTIVATIONDATAMETHODOLOGYRESULTSCONCLUSIONS
COST Action ES1206 - GNSS4SWEC, Final Workshop, ESTEC, Netherlands, Feb 21-23, 2017
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ZTD,meseriesmodelling:a) allsignificantperiodics,trend+theiruncertain,es,b) anopVmalnoisemodeldeliveredwithMaximumLikelihood
EsVmaVon(MLE)intheHectorsogware(Bosetal.,2013).
KlosA.etal.:„NoisecharacterisVcsinZenithTotalDelay…”
( ) ( )( )( )( )( )
( )( ) iZTDn
jjij
k Rikk
Rikk
RiRi
ttHd
ttfCttfSttvZTDtZTD
ε
ππ
+⋅+
+⎥⎦
⎤⎢⎣
⎡−⋅⋅+
+−⋅⋅⋅+
+−⋅+=
∑
∑
=
=
1
6
1
,
2cos2sin
MOTIVATIONDATAMETHODOLOGYRESULTSCONCLUSIONS
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Temporalvaria,onsofZTD
KlosA.etal.:„NoisecharacterisVcsinZenithTotalDelay…”
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Temporalvaria,onsofZTD
KlosA.etal.:„NoisecharacterisVcsinZenithTotalDelay…”
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NoiseanalysisofZTD:a) aninnovaVveapproachof
autoregressiveprocesspluswhitenoise(AR(4)+WH),
b) choicebasedontheBICandMLEandalso,asacompromisebetweenbothmenVonedandVmeofcomputaVons.
KlosA.etal.:„NoisecharacterisVcsinZenithTotalDelay…”
tZTDZTD
ZTDZTDZTD
aii
iii
+⋅+⋅+
+⋅+⋅=
−−
−−
43
21
43
21
εφεφ
εφεφε
MOTIVATIONDATAMETHODOLOGYRESULTSCONCLUSIONS
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Median amplitudes of noise (mm)±1-IQR Climate zone WN AR
Tropical 13.00±5.67 9.59±8.12 Dry 9.23±6.18 6.80±5.72
Warm temperate 9.70±8.28 8.75±7.93 Continental 8.77±7.62 7.07±6.03
Polar and Alpine (NH) 7.17±6.45 4.85±4.06
Polar and Alpine (SH) 8.91±8.05 4.07±3.60
Median coefficients of AR(4)±1-σ Climate zone AR(1) AR(2) AR(3) AR(4)
Tropical 0.90±0.08 0.05±0.08 0.01±0.03 0.03±0.01 Dry 0.78±0.04 0.19±0.03 0.05±0.01 0.01±0.01
Warm temperate 0.72±0.03 0.17±0.02 0.08±0.01 -0.01±0.01 Continental 0.80±0.02 0.08±0.01 0.09±0.01 -0.03±0.01
Polar and Alpine (NH) 0.61±0.02 0.27±0.01 0.11±0.01 -0.02±0.01
Polar and Alpine (SH) 0.61±0.01 0.28±0.01 0.13±0.01 0.01±0.01
Median fraction of AR±1-IQR Climate zone
Tropical 0.33±0.22 Dry 0.30±0.23
Warm temperate 0.44±0.37 Continental 0.40±0.31
Polar and Alpine (NH) 0.26±0.21
Polar and Alpine (SH) 0.21±0.18
MOTIVATIONDATAMETHODOLOGYRESULTSCONCLUSIONS
COST Action ES1206 - GNSS4SWEC, Final Workshop, ESTEC, Netherlands, Feb 21-23, 2017
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Ra,osofthetrenduncertainVesderivedwithAR(4)+WH(σAR(4)+WH)andWH-only(σWH):
KlosA.etal.:„NoisecharacterisVcsinZenithTotalDelay…”
WH
WHARratioσ
σ += )4(
MOTIVATIONDATAMETHODOLOGYRESULTSCONCLUSIONS
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MOTIVATIONDATAMETHODOLOGYRESULTSCONCLUSIONS
Ra,osofthetrenduncertainVesderivedwithAR(4)+WH(σAR(4)+WH)andWH-only(σWH): WH
WHARratioσ
σ += )4(
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MOTIVATIONDATAMETHODOLOGYRESULTSCONCLUSIONS
Ra,osofthetrenduncertainVesderivedwithAR(4)+WH(σAR(4)+WH)andWH-only(σWH): WH
WHARratioσ
σ += )4(
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MOTIVATIONDATAMETHODOLOGYRESULTSCONCLUSIONS
Ra,osofthetrenduncertainVesderivedwithAR(4)+WH(σAR(4)+WH)andWH-only(σWH): WH
WHARratioσ
σ += )4(
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Summingup:1. ThemaximaofannualcurvefallbetweenJulyandAugustfortheNorthern
Hemisphere,whilebetweenJanuaryandFebruaryfortheSouthernHemisphere.Thelargestamplitudesofdailyoscilla,onsarefoundforstaVonsinthetropicalzone,whilethoseinbothpolarandAlpinezonesarealmostflat.
2. TheAR(4)+WHnoisemodelisfoundtobeop,malforZTD,meseriesbasedontheBICandMLEvalues.Whitenoise,whichiswidelyassumedforZTDVmeseries,doesnotfitZTDresidualsatall.
3. 53of120examinedtrendsbecameinsignificant,whentheopVmumnoisemodelwasemployed,comparedto11insignificanttrendsforpurewhitenoise.
4. TheuncertaintyoftheZTDtrendsmaybeunderes,matedbyafactorof3to12comparedtothewhitenoiseonlyassumpVon.
KlosA.etal.:„NoisecharacterisVcsinZenithTotalDelay…”
MOTIVATIONDATAMETHODOLOGYRESULTSCONCLUSIONS
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Acknowledgments.AnnaKloswassupportedbyCOSTAcVonES1206GNSS4SWEC(gnss4swec.knmi.nl)duringherstayattheUniversityofLuxembourg.JanuszBoguszissupportedbythePolishNaVonalScienceCentregrantno.UMO-2016/21/B/ST10/02353.AddisuHunegnawisfundedbytheUniversityofLuxembourgIPRsGSCGandSGSL.KibromEbuyAbrahaisfundedbytheFondsNaVonaldelaRecherche,Luxembourg(ReferenceNo.6835562).ThecomputaVonalresourcesusedinthisstudywerepartlyprovidedbytheHighPerformanceCompuVngFacilityattheUniversityofLuxembourg(ULHPC).WeacknowledgeIGS/TIGAforprovidingtheGNSSdataandCODEfortheirproducts.
Thankyou!KlosA.etal.:„NoisecharacterisVcsinZenithTotalDelay…”
MOTIVATIONDATAMETHODOLOGYRESULTSCONCLUSIONS
See: Klos,A.,Hunegnaw,A., Teferle, F.N.,Abraha, K.E., Ahmed, F., and Bogusz, J.: Noise characterisVcs inZenith Total Delay from homogeneously reprocessedGPS Vme series, Atmos. Meas. Tech. Discuss., doi:10.5194/amt-2016-385,inreview,2016.
