vie sim - vievswiki.geo.tuwien.ac.at · vievs and vie_sim a r t i f i c i a l a r t i f i c i a l n...

VieVS User Workshop

7 – 9 September, 2010

Vienna

VIE_SIMVIE_SIMAndrea Pany

VieVS User Workshop 2010 2

Why simulations?generate artificial delay observables –useful to test

new scheduling strategiesdifferent station network geometriesantenna specifications...




generate zero input NGS files – useful to test the impact of different models in theanalysis


What is simulated?

o-c = (zwd2·mf(el2) + clk2) – (zwd1·mf(el1) + clk1) + wnbsl


What is simulated?stationstation 22 stationstation 11



What is simulated?

zwd - troposphere zenith wet delay

provided by a turbulence simulatorbased on the approach by Nilsson et al. (2007)accounts for spatial and temporal correlations

stationstation 22 stationstation 11



What is simulated?

mf(el) - mapping function (elevation)


zenith

mapping function


you should use thesame mf for the creationof the simulated files andfor the processing of thesimulated data – unlessyou want to study mf errors


What is simulated?

clk - station clock

simulated as sum of a random walk andan integrated random walk processaccording to Herring et al. 1990




What is simulated?

wnbsl - white noise per baseline




VIE_INITVIE_INIT

VIE_MODVIE_MOD

VIE_SIMVIE_SIM

VieVS and VIE_SIM


VIE_INITVIE_INIT

VIE_MODVIE_MOD

VIE_SIMVIE_SIM

VieVS and VIE_SIM

artific

ial

artific

ial

NGS NGS fil

esfiles


VIE_INITVIE_INIT

VIE_MODVIE_MOD

VIE_SIMVIE_SIM

VIE_INITVIE_INIT

VIE_MODVIE_MOD

VIE_LSMVIE_LSM

VieVS and VIE_SIM

artific

ial

artific

ial

NGS NGS fil

esfiles


Data flow in VIE_SIM

vie_sim

scanantenna

simparamparamfile

INPUTINPUT


Data flow in VIE_SIMINPUTINPUT az, el and mjd

are extractedand sorted bystation

vie_sim

scanantenna

simparamparamfile



sim_swdsim_clksim_wn

INPUTINPUT az, el and mjdare extractedand sorted bystation

vie_sim

scanantenna

simparamparamfile




vie_sim


group delaysare formedand storedscanwise

scanantenna

simparamparamfile




vievs2ngsvie_sim


group delaysare formedand storedscanwise

scanantenna

simparamparamfile




vievs2ngsvie_sim


group delaysare formedand storedscanwise OUTPUTOUTPUT

NGS-filesDATA/SIM

scanantenna

simparamparamfile


The output of VIE_SIMNGS-files


The output of VIE_SIMNGS-fileswe simulate the (o-c) vector and write the(o-c) + c to the observed value in theNGS-files


The output of VIE_SIMNGS-fileswe simulate the (o-c) vector and write the(o-c) + c to the observed value in theNGS-filesionosphere correction and cable cal needto be taken into account


The output of VIE_SIMNGS-fileswe simulate the (o-c) vector and write the(o-c) + c to the observed value in theNGS-filesionosphere correction and cable cal needto be taken into accountinterface for exchange of simulated data


Before running VIE_SIMrename the OPT files for the sessions forwhich you want to simulate (if OPT filesexist)


Before running VIE_SIMrename the OPT files for the sessions forwhich you want to simulate (if OPT filesexist)Do not use any outlier files!


Before running VIE_SIMrename the OPT files for the sessions forwhich you want to simulate (if OPT filesexist)Do not use any outlier files!make sure to set the quality code limit in the 2nd GUI to >9 (it is important that all observations are used for the simulation)


Before running VIE_SIMrename the OPT files for the sessions forwhich you want to simulate (if OPT filesexist)Do not use any outlier files!make sure to set the quality code limit in the 2nd GUI to >9 (it is important that all observations are used for the simulation)After the simulation you can process thesimulated data with any options you like!


start VieVS as usual

How to start the simulator




in the first GUI choose the sessionsfor which you want to simulate



in the first GUI choose the sessionsfor which you want to simulate

then choose to runVIE_SIM



do not use outlier files!if OPT files exist,

rename them before starting the simulator



set the qualitycode limit to a number > 9



The simulator GUIchoose the

parameters to besimulated


The simulator GUIenter the number of

days and a startingpoint for the runningnumber of the NGS files


The simulator GUIchoose a file

containing thesimulation parameters(can be stationspecific) …


Simulation parameter file

station names (8 characters)



turbulence parametersCn refractive index structure constant [10 -7m -1/3]H effective height of wet troposphere [m]vn, ve components of the wind vector [m/s]



a priori zenith wet delay [mm]



correlation interval [h] andstepwidth [m] for the numericalintegration



clock Allan Standard Deviation (ASD)



white noise [ps]


The simulator GUI… or directly enter

the values – these will then be applied to all stations


The simulator GUIwrong units! has to

be entered in1e-7 m -1/3


The simulator GUIadditional option: set

reference clock to zero


simulatedsimulated NGS NGS filesfiles are stored to VieVS / DATA / SIM / year

Where the data are stored

simulated NGS files are stored to VieVS / DATA / SIM / yearin DATA / LEVEL4 / your_dir you find




a MATLAB structurearray that containsazaz, el, and MJD, el, and MJDsorted by stationstored only oncefor each session



a MATLAB structurearray that containsthe mappingmapping functionfunctionsorted by stationstored only oncefor each session



a MATLAB structurearray that containsthe simulatedsimulated correlationcorrelationmatricesmatrices for each stationstored for eachsimulation



a MATLAB structurearray that containsthe simulatedsimulated valuesvalues ofofswdswd, , clkclk, and , and wnwnfor each stationstored for eachsimulation


How to process simulated data

choose to usesimulated data


select the simulatedNGS file(s)


then proceed as withreal data



Validation of the simulatorcomparison of real and simulated data for theCONT05 experiment:


Validation of the simulatorcomparison of real and simulated data for theCONT05 experiment:two sets of turbulence parameters (Nilsson and Haas, JGR, 2010)

radio sonde derived (VLBI2010 Progress Report)GPS derived




ASD 1e-14 @ 50 min, wn set to the formal delay error reported for CONT05




ASD 1e-14 @ 50 min, wn set to the formal delay error reported for CONT0525x15 days simulated -> median baselinelengths computed


Validation of the simulatorradio sondederivedturbulenceparameters


Validation of the simulator

GPSderivedturbulenceparameters


PLEASE MIND THAT VIE_SIM IS STILL WORK IN PROGRESS!

IT MIGHT CRASH INSOME CASES!


problems? questions? mail to [email protected]

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