# On the Integration of VLBI Observations to GENESIS into Global VGOS Operations
## 4 Results
### Mixed Schedules  
For the generation of mixed schedules, GENESIS is added as an additional source in the scheduling with MRTs from 1 to 10 min in 1 min intervals. The weight factors determined in Section 4.1 are applied in the scheduling. Figure 9 shows the distribution of satellite and geodetic source scans on local skies for selected stations based on a 24 h schedule with an MRT of 2 min for network C. It can be seen that scans of GENESIS are scheduled at regular intervals if the satellite is visible from at least two stations. The skyplot for Ny-Alesund, which is located at a latitude of about 79\({}^{\circ}\) north, shows a large number and the most equal distribution of satellite scans among the selected stations. Wettzell, located at a latitude of about 49\({}^{\circ}\) north, has many GENESIS scans towards the north. In the other directions, scans of GENESIS are more sparsely scheduled. Katherine and Kokee show significantly fewer and less equally distributed scans of GENESIS compared to Ny-Alesund. Due to the nature of the orbit, the stations Katherine and Kokee, located at latitudes of about 14\({}^{\circ}\) south and 22\({}^{\circ}\) north, respectively, exhibit shorter visibilities to the satellite. The total visibility of GENESIS, calculated by the time the satellite is above 5\({}^{\circ}\) elevation and visible from at least one other station, is 7.1 h per day for Ny-Alesund when averaging over 10 days. For Katherine and Kokee, the visibility is 3.8 h and 4.1 h. This underlines that even the station with the most visibility to GENESIS has on average about 17 h a day in which regular VLBI observations can be performed. However, it also shows that there is a strong bias between observation times across different latitudes, potentially leading to a bias in the determination of the frame tie.  
Figure 10 shows the number of stations with visibility to GENESIS above 5\({}^{\circ}\) elevation for networks A, B, and C within 24 h. It also visualizes whether GENESIS is in the northern  
Figure 8: VGOS schedule optimization for network A. Out of 64 tested schedules, the results from the five schedules showing the best repeatability values in the average station position and Earth orientation parameters (EOPs) are shown for network A. Additionally, the corresponding number of scans and observations are given.  
Figure 9: Distribution of satellite and geodetic source observations on local skies for (**a**) Ny-Alesund, (**b**) Wettzell, (**c**) Katherine, and (**d**) Kokee based on a 24 h schedule with a minimum repeat time (MRT) of 2 min for network C.  
hemisphere (NH) or the southern hemisphere (SH) during the time. The imbalance between the number of stations between NH and SH is caused by the antenna networks. The majority of stations are located in the NH. Only a maximum of seven stations are located in the SH for network C. The figure shows that for all three networks, there are periods where GENESIS is visible from only one station. During these times, no observations can be performed, as no baseline observation is possible.  
GENESIS is visible from different surface areas of the Earth with every satellite orbit revolution. This leads to the effect that the geometric configuration of stations and satellites vary from one day to another. By conducting VLBI experiments on different days, each 24 h session will provide different numbers of scans and observations. Therefore, the analysis investigating the VGOS performance with mixed schedules (step 2), presented in Section 4.3, and the frame tie with GENESIS for 24 h sessions (step 3), presented in Section 4.4, are not based on a single experiment, but on four experiments, each separated by one week, to account for this variation in the geometric configuration between stations and satellite.