A VGOS CRF fully consistent with the S/X frames preliminary results

The development of the Very Long Baseline Interferometry (VLBI) Global Observing System (VGOS) is expected to enhance the accuracy of delay estimates obtained from VLBI observable in fulfillment of the challenging demands referred to as GGOS (Global Geodetic Observing System) goals. A high-precision VGOS celestial reference frame (CRF) is essential for achieving these goals. Besides K-band and X/Ka-band products, the current realization of ICRS (International Celestial Reference System), ICRF3, includes VLBI observations from the S/X IEEE frequency bands of legacy VLBI observations until March 2018. Based on 6366 S/X-band and 280 VGOS sessions of IVS (International VLBI Service of Geodesy and Astrometry), we present a preliminary VGOS CRF that is fully consistent with S/X CRF, TRF and EOP (Earth Orientation Parameters). The consistency is achieved through the application of local ties between VGOS and S/X VLBI stations applying NNR+NNT constraints to S/X station coordinates only and NNR constraints to S/X radio source coordinates only, while defining and estimating the full set of five EOP identical parameters for both types of VLBI observations, VGOS and S/X, i.e. in terms of global ties. Furthermore, we will present a comparison to the consistent realization of data and geodetic parameters obtained from S/X and VGOS observations alone. Concluding, several global solutions determined for S/X and VGOS with different sets of datum will be discussed and quantitatively compared in our work.