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Favorable locations for new VGOS antennas in India depending on the assessment of geodetic parameters and environmental factors

Dhar, Sujata; Glaser, Susanne; Heinkelmann, Robert; Schuh, Harald; Balasubramanian, Nagarajan; Dikshit, Onkar

VLBI simulation studies are carried out to investigate the impact of any proposed station or strategy on the geodetic parameters, such as Earth Orientation Parameters (EOP) and Terrestrial Reference Frame (TRF). In general, such studies are performed for making decisions on any new development in the existing VLBI network. Thus, for selecting the favorable locations for establishment of a VLBI antenna in India, simulation studies are performed on 42 potential locations to cover the whole Indian subcontinent. Furthermore, the simulation setup is divided into four scenarios that consider the current and future situations of the global VLBI network. Extensive simulation strategy is applied with optimized scheduling for each network geometry, Monte-Carlo simulations and analysis in the VieSched++ software. Since only the simulation results are thought to be insufficient for a thorough evaluation of the realistic performance of locations, environmental factors are also investigated in the current study. The environmental factors affecting the operation and vulnerability of the VLBI technique at the potential locations are also incorporated in the present study. For this, a weighted scoring model is developed with the scores and weights based on the probable impact and occurrence frequency of disrupting environmental events, respectively. This approach will avoid the possibility of new VLBI station ending up in an unfavorable location in India and, underperforming substantially in terms of the achieved improvement of geodetic parameters as determined from the simulation study. The VLBI Global Observing System (VGOS) network is being established at a global level to create a uniformly distributed network of the next generation VLBI system to meet the goals of the Global Geodetic Observing Systems (GGOS). India is planning to establish its first VGOS antenna, and therefore, this study helps to mark the high-performance favorable locations for VGOS. The improvements in geodetic parameters of favorable locations identified in the simulation study are 6.7–11.2% in the first scenario, 12.8–46.8% in second scenario, 9–20.5% in third scenario and 2.9–6.1% in fourth scenario. The favorable locations outperform other Indian locations by a factor of 1.1–5.8. In addition to that, the Indian locations having environmental factors that might affect the VGOS adversely are not portrayed as the favorable choice.
Published in: Earth, Planets and Space, 10.1186/s40623-023-01794-8, Springr Nature