Current status of VLBI Intensive sessions

Abstract

Very Long Baseline Interferometry (VLBI) is the only space-geodetic technique capable of determining the full set of Earth Orientation Parameters (EOP) and celestial reference frames and it makes important contributions to the realisation of terrestrial reference frames. Standard VLBI sessions with a duration of 24 hours are usually observed on Mondays and Thursdays with a global network of up to 15 stations. Due to the large number of observations acquired during these VLBI sessions, all of the above-mentioned parameters of interest can be determined. However, the turnaround time for product delivery of standard VLBI sessions can take up to several weeks. Intensive VLBI sessions, or short Intensives, are one-hour sessions between 2 to 3 stations used for the rapid determination of UT1-UTC. Due to their much shorter turnaround time for product delivery, they enable us to monitor the Earth's rotation phase regularly.