DOI: https://doi.org/10.48436/5f0gc-rgb83

Time series of VLBI radio source positions at X-band

Hana Krasna, TU Wien, 2025 Aug 16
Vienna Center for VLBI (VIE)
https://www.vlbi.at
hana.krasna@tuwien.ac.at

Solutions: vie_sx_250816a_sts.txt and vie_sx_250816b_sts.txt 

Time span: Data from 1990.0 until 2025.5
Origin of input data: Databases from IVS data center, usno observing program if not from IVS
Software used for analysis: VieVS v4.0

Number of radio sources with session-wise estimated coordinates: 5676 in vie_sx_250816a, 5675 in vie_sx_250816b
Positions of defining ICRF3sx radio sources which are not included in the respective _sts.txt file (~150) were fixed in the adjustment


Source coordinates
   - Apriori source coordinates: ICRF3sx
   - Amplitude of Galactocentric acceleration vector: 5.8 uas/yr
   - Epoch of coordinates: 2015.0
   
   
Parameterization
   - Clocks: PWLO 60 min, 1 rate, 1 quadratic term
   - Troposphere: zenith wet delays: PWLO 30 min; gradients: PWLO 3 h
   - Earth orientation: PWLO, ERP at 0 UTC, nutation for the middle of the session
   - Station positions and velocities: position estimated with NNT/NNR on ITRF2020-u2023, velocities fixed to ITRF2020-u2023
   - Antenna axis offsets: fixed
   - BCO: for larger than 3 sigma

General information about the VLBI analysis done at VIE analysis center: Krasna et al. (2023), https://doi.org/10.1051/0004-6361/202245434

The International VLBI Service for Geodesy and Astrometry (IVS) and all its components are acknowledged for providing VLBI data.