Prospective study of high geodetic resolution to future VGOS reference point determination

The fast slewing rate and wide band of the VLBI2010 Global Observing System (VGOS) telescopes are beneficial to procure more observations and to obtain VLBI reference points (RPs) of high precisions. Meanwhile, with the development of synchronous tracking of fixed targets on telescopes during the observing, the RPs also can be determined in near real time based on a frame defined by other techniques. These opportunities provide us a possibility to explore the high geodetic resolution of VGOS telescopes. We design a thermal variation in RP as true values, and schedule a synchronous session of VGOS and target point (TP) series observing. Then VGOS delays and TP series are simulated and solved via piecewise functions. The results show that the accuracy of vertical component of the RP could be determined at an accuracy of 0.5 ± 0.3 mm in an hour using TP series, whereas the vertical components of RP solved by using VGOS delay measurements have a greater uncertainty due to the random error in the simulated atmosphere and bad radio source sky coverage in a shorter time interval. Some details in the data processing and accuracy evaluation are also introduced. Keywords: Reference point, VGOS, Geodetic resolution, Reweighting, Indirect metho