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VIE_ LSM

VIE_ LSM. Kamil Teke and Johannes Böhm. Introduction. v ie_lsm is a module of VieVS, which estimates geodetic parameters with least squares adjustment from VLBI observations. Estimated parameters are:

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VIE_ LSM

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  1. VIE_LSM Kamil Teke and Johannes Böhm

  2. Introduction • vie_lsm is a module of VieVS, which estimates geodetic parameters with least squares adjustment from VLBI observations. • Estimated parameters are: • quadratic polynomial coefficients of clocks (offset in cm, rate in cm/day, and quadratic term in cm/day2) plus continuous piecewise linear offsets (CPWLO) of clocks in cm, • zenith wet delay (ZWD) CPWLO in cm, • troposphere north and east gradients CPWLOin cm, • Earth orientation parameters (EOP) CPWLOin mas and ms, • TRF coordinates of antennas in cm (CPWLO or oneoffset per session), • CRF coordinates of sources as CPWLO in mas. • Since, the standard deviations of observations are so small, 1 cm added before weights are formed. Weight matrix of observations is diagonal (units are in 1/cm2). Currently, no down weighting is applied due to elevation angles of the observations. VieVS User Workshop 2011

  3. Introduction • estimates constrained (relative or absolute)to zero with a large or a small standard deviation (loose or tight). This is due to connect the parameters which have no observation in the corresponding estimation interval. • Realistic standard deviations should be assigned to the constraints. If not then outlier observations in small number in an estimation interval will cause unrealtistic estimates. offset(t+1) - offset(t) = 0 ± mc_rel relative constraints Example: mc_rel= 30 mas/day  Xpol CPWLO relative constraints are loose. mc_rel = 0.001 mas/day  XpolCPWLO relative constraints are tight. offset(t) = 0 ± mc_abs absolute constraints Example: mc_abs= 2 mm  Troposphere east gradients absolute constraints are loose. mc_abs= 0.01 mm  Troposphere east gradients absolute constraints are tight. VieVS User Workshop 2011

  4. Continuous piece-wise linear offset functions (CPWLO) VieVS User Workshop 2011

  5. Partial derivatives of the delay model w.r.t. a sub-daily parameter to be estimated at consecutive epochs and are the estimated offsets ofa parameter at epochs e.g. ΔUT1 is the estimated parameter at epochs 15:00 and 16:00 UTC VieVS User Workshop 2011

  6. LS Adjustment design matrix of real observation equations design matrix of pseudo-observation equations (constraints) bc is a zero vector (due to NNT and NNR conditions parameter vector (estimates) variance-covariance matrix of the estimates VieVS User Workshop 2011 6

  7. VLBI clock error quadratic polynomial for each clock CPWLO for each clock e.g. at each UTC integer hour (t1 and t2) total clock error at epoch t VieVS User Workshop 2011

  8. Modeling clock breaks VieVS User Workshop 2011

  9. Troposphere delay reduced from observations a priori to the adjustment estimated estimated estimated VieVS User Workshop 2011

  10. VIE_LSM GUIs VieVS User Workshop 2011

  11. VIE_LSM GUIs VieVS User Workshop 2011

  12. VIE_LSM GUIs VieVS User Workshop 2011

  13. VIE_LSM GUIs VieVS User Workshop 2011

  14. VIE_LSM GUIs VieVS User Workshop 2011

  15. VIE_LSM GUIs VieVS User Workshop 2011

  16. VIE_LSM GUIs VieVS User Workshop 2011

  17. VIE_LSM GUIs VieVS User Workshop 2011

  18. VIE_LSM GUIs VieVS User Workshop 2011

  19. VIE_LSM GUIs VieVS User Workshop 2011

  20. VIE_LSM GUIs Hana will talk about this GUI VieVS User Workshop 2011

  21. Thank you so much for your attention! VieVS User Workshop 2011

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