PowerPointPrsentation

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Sixth IVS Analysis Workshop, Noto, Italy
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Activities at the BKG Data and Analysis Centre
Leipzig
Volkmar Thorandt, Gerald Engelhardt, Dieter
Ullrich, Reiner Wojdziak Bundesamt für
Kartographie und Geodäsie (BKG), Aussenstelle
Leipzig Karl-Rothe-Strasse 10-14, D-04105
Leipzig, Germany
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Contents
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• General Information
• Estimation of axis offsets
• The BKG EOP time series bkg00007 and bkgint04
• Quarterly updated solutions for submissions to
  IVS
• Submissions of tropospheric parameters to IVS
• Submissions of daily SINEX files to IVS
• UT1 time series from 1 hour data Tsukuba-Wettzell
• Results from nearly 3 years data of Tigoconc
• Test of unstable radio sources
• Technology
• Outlook

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Aufgaben
General Information
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Tasks of the BKG Data and Analysis
Centre Operating the IVS Data Centre (GSFC,
OPAR, BKG) at BKG. Generation of calibrated
databases for the sessions correlated in Bonn
(IVS-T2, EUROPE, OHIG, etc.) Submission to the
IVS Data Centres. Continuation of EOP-series for
24h experiments (bkg00007.eops) resp. for
Intensive experiments (bkgint04) as contributions
to the IVS service and to Bulletin B. Quarterly
TRF and CRF solutions for the IVS. Long term
troposphere files (total zenith delay, wet
zenith delays, tropospheric gradients) for the
IVS. Daily SINEX files for the IVS. Participation
in software projects (REPA - stopped), the
objective was to port the Calc/Solve software
from UNIX to LINUX. Refining of analysis strategy
(i.e. handling of stable/unstable radio sources,
axis offsets, data flow)
Mirroring of IVS Data Centres
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Estimation of Axis Offsets
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• At BKG (Gerald Engelhardt) and GSFC (Dan
  MacMillan) two sets of axis offsets has been
  estimated to improve the used values.
• In cooperation with Volker Tesmer (DGFI) the IVS
  Analysis Coordinator Axel Nothnagel (GIUB)
  created the so-called Official list of VLBI
  antenna axis offsets
  http//giub.geod.uni-bonn.de/vlbi/IVS-AC/da
  ta/axis-offsets.html
• four kinds of values
• locally measured
• weighted means of BKG and GSFC values
• 4 stations with non-significant averages
  (MIAMI20, MIZNAO10, OVRO 130, URUMQI) 0.0
  recommended
• axis offsets estimated only by one group (BKG or
  GSFC)

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The BKG EOP time series bkg00007
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• EOP series bkg00007 extracted from a global
  solution with 24 hours VLBI sessions from 1984 on
  (altogether about 3000 sessions)
• Main parameter types are EOP, global station
  coordinates and velocities, radio source
  positions.
• Axis offsets recommended by IVS Analysis
  Coordinator.
• Minimal constraints for the datum definition are
  applied to get
• Zero net rotation and zero net translation
  for 26 selected
• station positions and velocities with
  respect to VTRF2003.
• (VLBI Terrestrial Reference System see
  http//giub.geod.unibonn.de/vlbi/IVSAC/vtrf2003/no
  thnagel02.pdf)
• Zero net rotation for 212 defining sources
  with respect to ICRF-Ext.1
• Station coordinates of TIGOCONC (Chile) and
  SVETLOE (Russia) estimated as local parameters
  in each session

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The BKG UT1-UTC time series bkgint04
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• UT1-UTC time series bkgint04 is generated with
  fixed TRF (VTRF2003) and fixed CRF derived from
  the global BKG solution for EOP determination
  (bkg00007.eops)
• - estimated parameter types only UT1,
  station clocks, zenith troposphere
• - currently about 1500 UT1 intensive
  sessions (including Tsukuba-Wettzell sessions) ,
  analysed for the period between 1999.01.01 and
  2005.04.20

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UT1 time series (Intensives Tsukuba/Kokee -
Wettzell)
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UT1 time series (Intensives Kokee - Wettzell)
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UT1 time series (Intensives Tsukuba - Wettzell)
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UT1 time series Tsukuba-Wettzell / Kokee-Wettzell
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• Kokee-Wettzell
• 537 Sessions (02JUN28XU, I02179 - 05MAR23XU,
  I05082)
• Tsukuba-Wettzell
• 125 Sessions (02JUL01XK, K02182 - 05MAR19XK,
  K05078)
• Sessions are included in BKG Intensive Series
  BKGINT04
• Results
• Tsukuba-Wettzell Kokee-Wettzell
• -------------------------------------------------
  ----------------------------------
•  Number of sessions 125
  537
• 2002.07.01 - 2003.12.20
•  WRMS derived from 16 microsec 17
  microsec
• the differences to C04
•  Mean formal standard 11 microsec
  17 microsec
• deviation from Solve
• -------------------------------------------------
  ----------------------------------

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Quarterly updated solutions for submission to IVS
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• Quarterly updated solutions are estimated for the
  IVS products TRF and CRF.
• - There are no differences in the solution
  strategy compared to the continuously computed
  EOP time series bkg00007.
• - Format of the results
• IERS format for the radio source
  positions and
• SINEX format, version 2.1 for station
  coordinates
• and velocities

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Submissions of tropospheric parameters to IVS
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• The BKG VLBI group submits so-called longterm
  tropospheric parameters to the IVS (wet and total
  zenith delays, horizontal gradients) for sessions
  from 1984 on.
• Tropospheric parameters are extracted from
  the global solution for EOP time series bkg00007
  and transformed to SINEX format for tropospheric
  estimates.

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Submissions of daily SINEX files to IVS
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• The BKG VLBI group submits daily SINEX files as
  base solutions for the IVS time series of
  baseline lengths and for combination techniques.
• For this purpose additionally to the above
  described global solutions independent session
  solutions for the parameter types station
  coordinates, EOP, and nutation parameters are
  computed.

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Results from nearly 3 years data of station TIGO
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• Coordinate series of Tigoconc in bkg00007 from
  2002.05.13 to 2005.03.05 (243 sessions).
• By using a straight-line model for fitting the
  Tigoconc coordinate series, useful velocity
  information about Tigoconc for N, E, U component
  could be estimated.
• Results
• 
  Station velocity Standard deviation WRMS
• mm/year
  mm/year mm
• -------------------------------------------------
  --------------------------------------------------
  --------
• Tigoconc N-component 17.4
  0.9 12.1
• Tigoconc E-component 31.5
  0.6 8.9
• Tigoconc U-component 8.5
  2.1 26.2
• -------------------------------------------------
  --------------------------------------------------
  --------
•  

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Results from nearly 3 years data of station TIGO
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Results from nearly 3 years data of station TIGO
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Results from nearly 3 years data of station TIGO
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Test of stable / unstable radio sources
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• See presentation of Gerald Engelhardt

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Technology Data Flow and Analysis at BKG
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Analysis Centre OPAR
GSFC
Correlator
mirror
mirror
mirror
input
input
access to the IVS Data Centre
automated procedures for mirroring, data
filtering und pre-analysis (prae_solve)
public
internal
Operational Data Centre
PRODUCTS EOP TRF CRF Long term trop.
Parameters Daily Sinex Files Databases NGS-Files C
alibration files (met,cab)
interaction (Calc/Solve) (starting with
correlator-output) outliers, ambiguities, weightin
g, clock jumps, parametrisation
technology
automated procedures for creating of
IVS-products (post_solve)
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Outlook
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• Refining of the solution strategy for series
  bkg00007
• - inclusion of Vienna Mapping Function
• - handling of stable/unstable radio source
  positions
• - data flow
• Improvement of Pre- and PostSolve Software
• Scheduling of IVS experiments