Analysis of the EOPs from Independent Parallel VLBI Sessions

Time series of Earth Orientation Parameters (EOP) have been obtained from independent parallel Very Long Baseline Interferometry (VLBI) networks NEOS-A and CORE-A using OCCAM 5.0 software.This paper presents the results and their detailed consideration. The EOP time series are approximated by linear functions so offset and rate of the differences between the networks (NEOS — CORE) for the same epoch can be estimated. It appears that biases between two EOP systems are negligibly small in 1996–1997 years, but are increasing in time. The study is important to make up an accurate International Celestial Reference Frame (ICRF) and International Terrestrial Reference Frame.