STRATEGIC PLACEMENT OF THIRD VGOS TELESCOPE IN INDIA FOR IMPROVED EOP ESTIMATION

Very Long Baseline Interferometry (VLBI) is the only space geodetic technique capable of directly observing Universal Time (UT1), along with determining all other Earth Orientation Parameters (EOP). This study explores improving EOP precision by identifying the optimal location for a third telescope within the Indian subcontinent, inspired by the Australian AuScope telescope configuration. Using Monte Carlo simulations with VieSched++ software, we evaluated the combined impact of multiple new stations, addressing a limitation in prior research that primarily focused on single-station evaluations. Our approach involves defining four reference networks, integrating legacy telescopes, global VGOS stations, and proposed VGOS stations. The Indian subcontinent is then divided into a 5 x 5 degree grid to identify potential locations for new VGOS telescopes, resulting in a total of 22 potential sites considered for this research. For each potential site, we sequentially add stations to the base reference network (Ref) and reference network incorporating two planned Indian telescopes (Ref-In), located in southern and northeastern India. The analysis compares EOP repeatability values after including the third station with those of Ref and Ref-In networks. Results suggest that while adding a third station does not significantly improve EOP precision, however it strengthens network redundancy. The findings indicate that the optimal placement for the third station lies in the western or northern regions of India, depending on the reference network.