SNR simulations for Genesis VT observations

Paper in proceeding, 2025

The signal-to-noise ratio (SNR) of Genesis signals on a baseline between two VLBI Global Observing System (VGOS) telescopes is a critical factor influencing data quality and delay estimation. The SNR on a given baseline depends on various factors, including the received power flux density (PFD) at each station. In traditional VLBI observations of quasars at cosmological distances, the incoming radio signals arrive at the ground stations with approximately equal power, resulting in a uniform PFD across identical telescopes. However, in the case of a VLBI transmitter (VT) onboard an Earth-orbiting satellite, the received signal power varies across different ground stations due to the dynamic geometrical configurations between the satellite and each station. In this study, we conduct simulations over a one-day period to compute the SNR for different baselines, considering various antenna gains for Genesis Band A (3100–3300 MHz) signals.