Impact of erroneous a priori information on the UT1-UTC determination from VLBI Intensive sessions (simulation study)

The dataset was generated by researchers from the TU Wien Department of Geodesy and Geoinformation and the ETH Zürich Department of Civil, Environmental and Geomatic Engineering, as a fundamental part of a study related to the analysis of the impact of erroneous a priori information on the UT1-UTC determination from VLBI Intensive sessions. The corresponding publication (title: "On the importance of accurate pole and station coordinates for VLBI Intensive baselines") has been submitted to the Journal of Geodesy. 

In addition, a conference paper, and presentations at the IVS General Meeting 2022, EGU General Assembly 2022 and REFAG 2022 are available.

Context and methodology

The dataset contains monthly simulated UT1-UTC values of an artificial global grid of VLBI antennas (VGOS) where realistic errors in the a priori values of the station coordinates, polar motion and nutation offsets are introduced. With the help of these simulated values the global impact of erroneous a priori information is analysed.

VieSched++ and VieVS (both developed at the TU Wien) were used to generate the schedules and simulations.

Technical details

The dataset is structured as follows. There are 7 subfolders in the zipped folder that contain the simulation results of the evaluations with modified a priori values:

• folder "errSTAu" - error of 5 mm introduced in the up-direction of the second station
• folder "errSTAe" - error of 5 mm introduced in the east-direction of the second station
• folder "errSTAn" - error of 5 mm introduced in the north-direction of the second station
• folder "errPMx" - error of 162 microarcseconds introduced in the x-component of the polar motion
• folder "errPMy" - error of 162 microarcseconds introduced in the y-component of the polar motion
• folder "errNUTx" - error of 162 microarcseconds introduced in the x-component of the nutation offsets
• folder "errNUTy" - error of 162 microarcseconds introduced in the y-component of the nutation offsets

Within these folders, there are .txt files with the following naming convention: "N%E%__N%E%_d#.txt".

• "N%E%__N%E%" represents the location (North and East in degrees = latitude and longitude) of the reference and remote station
• "d#" again shows the error that has been introduced in the simulation process
• The files contain the monthly simulation results of UT1-UTC and its accuracy in milliseconds.