VIE230917k: Celestial reference frame at K-band

Context and methodology

Global celestial reference frame solution from Very Long Baseline Interferometry based on K-band data until September 2023. Published are three files of the same solution with different reporting of uncertainties. The vgosDB are analyzed with VieVS software package. The methodology of the analysis follows description in Krásná et al. (2023).

Reported uncertainty

• VIE230917k_CRF_Err_lsm.txt reports formal errors from global LS adjustment
• VIE230917k_CRF_Err_icrf3k.txt follows ICRF3-K methodology and reports inflated errors with scaling factors:  1.5 RA,  1.5 De; and RA/Dec noise floor =  30/ 50 micro-arc-sec  
• VIE230917k_CRF_Err_decldep.txt reports declination dependent noise floor following Gordon et al. (AJ, 2026; Tab 1) - Inflated errors: scaling factors:  1.5 RA,  1.5 De; RA/Dec noise floor as function of declination

Technical details

• DATA START: 2002-05-15
• DATA END: 2023-09-17
• FREQUENCY BANDS: K
• ANALYSIS CENTER: VIE (TU Wien, Austria) 
• CONTACT: Hana Krasna (hana.krasna@tuwien.ac.at) 
• SOFTWARE: VieVS v4.0 
• TECHNIQUE: VLBI 
• EPOCH: J2000 frame at 2015.0 galactic aberration epoch with 5.8 uas/y GA amplitude  
• DATA ORIGIN:
  1. projects BR079, BL115, 128 and BL122 (Lanyi et al. (2010), Petrov et al. (2011));
  2. since 2014 Astro2Geo project: (de Witt et al. (2023), Krásná et al. (2023), Gordon et al. (AJ, 2026))
     • VLBA: BJ083, UD001, UD009, UD015, UD017 
     • HARTRAO-HOBART26: KS14, KS16-KS21 (+TIDBIN64, TIANMA65)
     • HARTRAO-YEBES40M: KM22-KM23 
     • KVN, YEBES40M, MOPRA, SEJONG: n23aw, n23jh
• vgosDB: Database creation and fringe-fitting done by David Gordon (USNO), Alessandra Bertarini (MPIfR), Jamie McCallum (UTAS)

Data format

Plain ASCII files.

Acknowledgements

The use of the Very Long Baseline Array under the US Naval Observatory's time allocation is acknowledged, which supports USNO's ongoing research into the celestial reference frame and geodesy. The VLBA is operated by the National Radio Astronomy Observatory, which is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

Radio telescopes observing K-band sessions within the Astro2Geo project are acknowledged https://sites.google.com/sarao.ac.za/k-bandastrogeovlbi/network