First VLBI experiments between Kashima and Wettzell for monitoring UT1

During 14 days UT1 was monitored by daily VLBI short experiments between Kashima and Wettzell (GJRO, German Japanese Earth Rotation Observations) in order to investigate short-term UT1 variations and to compare the results with those of another independent network, Wettzell and Westford (USA). Both UT1-series agree within 0.2msec if the regular IRIS pole positions are used, but there is still a remaining offset of 0.1 msec. The fortnightly period (13.66d) induced by earth tides was detected in the GJRO results with an increase of the theoretical amplitude by 5–10%. Using the data of the long experiment the baseline vector was also determined. The baseline length coincides with the Crustal Dynamics Project VLBI-campaign solution to within 1cm.