# On the Integration of VLBI Observations to GENESIS into Global VGOS Operations
## 4 Results
### Frame Tie with GENESIS in 24 h Experiments  
To investigate the expected frame tie accuracy, the mixed schedules are analyzed following the GENESIS processing. We evaluate the estimated station positions from observations of GENESIS. Figure 12 shows the station position repeatability of selected stations averaged over four 24 h sessions with network C, an MRT of 5 min, and orbit errors at the level of 3 cm. The stations are sorted from left to right by their latitude with Ny-Alesund representing the most northern and Hobart the most southern station. Ny-Alesund shows the best station position repeatability. It also has a large number of  
Figure 11: Degradation of VGOS results due to GENESIS. For each network A, B, and C, the station position repeatability, dUT1 repeatability, number of scans, and number of observations are shown when analyzing mixed schedules with MRTs for GENESIS between 1 and 10 min in 1 min intervals. The values are given as absolute values as well as percentages relative to the VGOS schedule reference. The analysis follows the VGOS processing. The number of scans and observations only refers to geodetic sources. scans and observations. Among the selected stations, Hobart shows the worst station position repeatability with the up-component being determined significantly worse than the north- and east-components. Although Hobart shows a similar number of scans as Ishioka, the number of observations is significantly less. This indicates that on average Hobart does not share many baselines with other stations per scan. The repeatability for Wettzell and Ishioka underline that the number of scans and observations are not the only elements affecting the station position repeatability. Wettzell shows more scans and observations than Ishioka. However, the station position repeatability is larger than for Ishioka. The reason for this could be the favorable antenna network geometry and connectivity for Ishioka leading to more advantageous baselines. With the stations sorted by their latitude, the number of scans underlines the general increase in visibility of GENESIS close to the polar regions due to the nature of the orbit. Figure 13 visualizes the station position repeatability averaged over all stations, the number of GENESIS scans, and the number of GENESIS observations for the three networks A, B, and C with MRTs from 1 min to 10 min in 1 min intervals. The four different orbit error magnitudes are at 0 cm (no orbit errors), 1 cm, 3 cm, and 5 cm. For all three networks, the station position repeatability deteriorates with larger MRTs. This is simply explicable by a decreasing number of scans and observations. Furthermore, as to be expected, the station position repeatability decreases with larger orbit errors of the satellite. The number of scans ranges from about 100 to 400 for network A, about 100 to 450 for network B, and about 100 to 500 for network C. With the increasing size of the utilized antenna network, GENESIS is visible from at least two stations for longer periods of time if newly added stations cover areas that were not previously seen by other stations. The improved visibility of networks B and C as compared to network A eventually leads to more scans at the same MRT, and while the difference in the number of scans between network A and C is at maximum about 100 scans, the number of observations differs significantly. The networks B and C show more than 3-4 times more observations than network A. Although not shown here, we tested shorter MRTs at 30 s, even removing the MRT. Instead of an improvement of the station position repeatability, the results are significantly worse. This is because the frequent observation of GENESIS leads to too few geodetic source observations and, consequently, a poor distribution of sources across the local skies of stations. This compromises the estimation of the troposphere and station positions. An MRT of 1 min leads to the best estimation of station positions.