Abstract:
© 2020, Pleiades Publishing, Ltd. Abstract: As of 2019, the International VLBI Service for Geodesy and Astrometry (IVS) has existed for 20 years. This service is the largest and most prominent organization that coordinates international activities in its field, which currently includes approximately 60 radio telescopes located in many countries from all continents. The IVS data center has accumulated more than 18 million observations obtained during more than 17 000 observation sessions, including more than 10 000 short sessions for rapid determination of universal time. This paper follows the dynamics of IVS development based on the statistical processing of the observational array accumulated in the IVS data center for 1979–2018. Statistics for observation years, stations, baselines, and radio sources are given. The evolution of observation statistics and the accuracy of the results obtained from the processing of VLBI observations is considered.