VIE_GLOB

VIE_GLOBHana SpicakovaVieVS User Workshop14 16 September, 2011Vienna

VieVS User Workshop 20112VIE_GLOB_V1dcompatible with VieVS Version 1d

parameters which can be estimated - from combination of more sessionsstation coordinates and velocities: TRFsource coordinates: CRFEarth orientation parameters

- session-wise as reduced parameterszenith wet delaytroposphere gradientsEarth orientation parametersstation and source coordinates (not suitable for global estimation)input datadatum free N-matrices (ATPA) and b-vectors (ATPl)VieVS/DATA/LEVEL2created within a normal run of VieVSLast GUI in VIE_LSM

VieVS User Workshop 20113data for VIE_GLOB will be stored in DATA/LEVEL2/How to run VIE_GLOB

VieVS User Workshop 20114VieVS/COMPILE/VIE_GLOB_V1d/vie_glob.mpath to the directory TEST_LEVEL2 with LEVEL2 datathe subdirectory TEST_OUT will be created in VieVS/OUT/GLOB/_ESTIMATES /_PLOTSeventually in: /CRF /TRF

only sessions with a lower RMS than chosen (in this case RMS < 2) will be used in the global adjustment

if ticked, N matrices and b vectors with reduced parameters from each session will be saved into VieVS/OUT/GLOB/BACKWARD_DATAINPUTOUTPUTGUI for RF

VieVS User Workshop 20115Terrestrial Reference FrameCelestial Reference FrameGUI for TRF

VieVS User Workshop 20116VieVS/DATA/GLOB/TRF/DATUM/REDUCE/DISCONT/VELOC/VELOC/TIES/

the original VLBI-DISCONT.txt file is provided at the web site http://vlbi.geod.uni-bonn.de/IVS-AC/data/VLBI-DISCONT.txt TRF_datum1.txtfew_observations.txtconst_velocity_8410.txttest.txtchoose between NNT/NNR or NNT/ NNR /NNS

VieVS User Workshop 20117GUI for CRFVieVS/DATA/GLOB/CRF/DATUM/FIXED_SOURCES/REDUCE/

choose between NNR or NNR + translation in declination condition

CRF_datum1.txttest.txtspecial_handling_39.txtTheoretical backgroundVieVS User Workshop 20118Sort parameters in the N-matrix and b-vectorReduction of parametersalways reduced: clock parameters, zwd and troposphere gradientscan be reduced: EOP, stations and sources not suitable for global solution

Stacking of the reduced normal equation systems

globally estimated p.reduced p.

Constraintszwd, troposphere gradients, EOPconstraints are chosen in VIE_LSM

station coordinates and velocitiesrelative constraints for velocitysame velocity for all coordinate intervals at one station (e.g. antenna repair)same velocity at stations in the same area (e.g. Hobart26 and Hobart12)datum definition

source coordinatesdatum definition

VieVS User Workshop 20119Datum definitionStation coordinates and velocitiesNNT/NNR condition constrained 12 parameters Helmert transformation(3 translation and 3 rotation components + their time derivatives w.r.t. time)NNT/NNR/NNS condition constrained 14 parameters Helmert transformation(3 translation , 3 rotation components and 1scale component + their time derivatives w.r.t. time)

Source coordinatesNNR conditionNNR condition + 1 translation parameterparameter dz accouns for a global translation of the source coordinates in declination, caused e.g. by inaccuracy of the tropospheric propagation correction for sources observed at low elevations) (Feissel-Vernier et al. (2006))

fixing selected sources to a priori coordinatesVieVS User Workshop 201110VieVS User Workshop 201111Final solutionapplying of the constraints

final solution for global parameters

estimates are stored as a structure array in Matlab format and as a txt fileVieVS/OUT/GLOB/_ESTIMATES/TEST_OUT/globsol_TEST_LEVEL2.matglob_results_TEST_LEVEL2.txt

Estimates - Example

VieVS User Workshop 201112VieVS/OUT/GLOB/_ESTIMATES/TEST_OUT/glob_results_TEST_LEVEL2.txtnames of sessionsnumber of sessionscorrections to station a priori coordinates and their standard deviations [cm]corrections to station a priori velocities and their standard deviations [cm/y]stations which were used for NNT/NNRepoch of the coordinates [mjd]start, end [mjd] of the interval (time between breaks)sessions with RMS>maxRMS

VieVS User Workshop 201113corrections to source a priori coordinates (RA, De) and their standard deviations [mas]

Estimates - Exampleestimates of EOP:dx, dy pole [mas]dut1 [ms]dX, dY [mas]and their standard deviationsResults

VieVS User Workshop 201114new catalogues (TRF and CRF) are created automatically in VieVS/OUT/GLOB/TRF/TEST_OUT/trf_TEST_LEVEL2.txtandCRF/TEST_OUT/trf_TEST_LEVEL2.txt

this new TRF catalogue can be used as input catalogue in VieVSPlots

VieVS User Workshop 201115VieVS/OUT/GLOB/_PLOTS/TEST_OUT/ant_activity_TEST_LEVEL2.epsant_map_TEST_LEVEL2.epsstations in sessions included in the global adjustmentmap of stations, blue circles: station included in NNT/NNRred circles: station excluded from NNT/NNRPlots

VieVS User Workshop 201116VieVS/OUT/GLOB/_PLOTS/TEST_OUT/sou_activity_TEST_LEVEL2.epssou_map_TEST_LEVEL2.epssources in sessions included in the global adjustmentmap of sources, blue circles: source included in NNRred circles: source excluded from NNRProcessing of a long time span of data (20 years or more)Problems

if e.g. EOP would be considered as global parameters (stacking at the overlapping time steps), the final N matrix would be too huge not possible to handle it at a normal PC

position of some sources is not stable enough to handle it as a constant value

unequal observation time at the stations at some stations the observation interval is not sufficient to estimate reliable velocity

VieVS User Workshop 201117Processing of a long time span of data (20 years or more)Problems

if e.g. EOP would be considered as global parameters (stacking at the overlapping time steps), the final N matrix would be too huge not possible to handle it at a normal PC

position of some sources is not stable enough to handle it as a constant value

unequal observation time at the stations at some stations the observation interval is not sufficient to estimate reliable velocity

VieVS User Workshop 201118

Processing of a long time span of data (20 years or more)Problems

if e.g. EOP would be considered as global parameters (stacking at the overlapping time steps), the final N matrix would be too huge not possible to handle it at a normal PC

position of some sources is not stable enough to handle it as a constant value

unequal observation time at the stations at some stations the observation interval is not sufficient to estimate reliable velocity

VieVS User Workshop 201119

In these cases the concerned parameters have to be excluded from the global adjustment by a session-wise reduction.

The vector x2 we get from a so-called back solution for each session:

Covariance matrix

VieVS User Workshop 201120Reduction

globally estimated p.reduced p.After running VIE_GLOB we know the vector x1 (global parameters)

ReductionIf the button in the 1st GUI of VIE_GLOB is ticked, all needed parameters for a back solution will be stored in: VieVS/OUT/GLOB/BACKWARD_DATA/TEST_OUT/i.e., N21, N22 and b2 for each session + some other information, e.g. description of the columns

VieVS User Workshop 201121After finishing of VIE_GLOB run VieVS/OUT/GLOB/backward_solution.min the source code you have to specify the name of the TEST_OUT and TEST_LEVEL2 directories and which reduced parameters you want to estimate

The estimated values will be written into .txt files in VieVS/OUT/GLOB/BACKWARD_SOLUTION/TEST_OUT/ asant_TEST_LEVEL2.txteop_TEST_LEVEL2.txtsou_TEST_LEVEL2.txttgr_TEST_LEVEL2.txtzwd_TEST_LEVEL2.txt

Backward solution: zwdVieVS User Workshop 201122

The estimates for each station can be plotted with:

VieVS/OUT/GLOB/plot_backward_zwd.m

VieVS User Workshop 201123Backward solution: tgrThe estimates for each station can be plotted with:

VieVS/OUT/GLOB/plot_backward_tgr.m

VieVS User Workshop 201124Backward solution: EOPThe estimates for each EOP can be plotted with:

VieVS/OUT/GLOB/plot_backward_eop.m

VieVS User Workshop 201125Backward solution: antenna coordinatesThe estimates for each station can be plotted with:

VieVS/OUT/GLOB/plot_backward_ant.m

VieVS User Workshop 201126Backward solution: source coordinatesThe estimates for each source can be plotted with:

VieVS/OUT/GLOB/plot_backward_sou.m

VieVS User Workshop 201127Thank you for your attention!