The Global VLBI Alliance

For more than 50 years, Very Long Baseline Interferometry (VLBI) has studied the Universe with the greatest detail. Radio telescopes around the world have joined forces to create formal VLBI networks, long standing international collaborations which also regularly cooperate to form combined arrays. A Global VLBI Alliance (GVA) has been set up to facilitate the flow of information between these VLBI networks, including sharing strategies, technical developments for compatibility, logistics, operations, and user support. The GVA also promotes and coordinates common observational campaigns with these existing networks, fosters and supports new VLBI activities, while increasing the visibility, scientific and societal impact of VLBI. The GVA moreover facilitates the interaction with the users, and serves as contact point and framework of collaboration of the VLBI networks and other astronomical facilities, in view of the growing need of multi-messenger studies. For example, the GVA is preparing the collaboration with the Square Kilometre Array Observatory (SKAO) to include the SKA as a very sensitive element in VLBI networks, as well as a mechanism to add long baselines to the SKA Phase 1 (SKA1) telescopes. The consortium will provide the VLBI equipment for the SKA telescopes and assist the coordination of VLBI Networks for joint observations with the SKA.