GASV: A New VLBI analysis software for Geodesy and Astrometry

We present GASV, a new Python-based software package for the analysis of Very Long Baseline Interferometry (VLBI) data. Designed for ease of installation and use, GASV supports both pipeline and interactive processing modes. The software ingests VLBI baseline delays and rates in standard formats (HOPS outputs and NGS card files) to estimate key geodetic and astrometric parameters, including station coordinates, Earth Orientation Parameters (EOP), source coordinates, clock parameters, and atmospheric models. We evaluate GASV's capabilities and performance, demonstrating that its parameter estimation accuracy for IVS INT, Regular, and CONT sessions is comparable to that achieved by the VLBI analysis centers at BKG and USNO. GASV represents a state-of-the-art tool, capable not only of high-quality session data processing but also of performing global analyses of long-term SINEX files to produce Celestial Reference Frame (CRF) and Terrestrial Reference Frame (TRF) solutions with reliable accuracy.