First VLBI Observations between Weilheim, Kashima and Nobeyama

Abstract

In September, 1990, the Weilheim (Germany) 30 m antenna was configured for geodetic VLBI by transporting a K-4 back-end system from Japan and the first observations were accomplished between Weilheim, Kashima (Japan) and Nobeyama (Japan). Quality of observations at Weilheim is good, although a crystal quartz clock phase-locked to a Cs frequency standard was used. It is demonstrated that a K-4 back-end system has good transportability and mechanical reliability in international VLBI observations. The data of the Weilheim-Kashima baseline are analyzed to determine the coordinates of the Weilheim antenna. Internal precision of the estimated coordinates is about 10 cm which is much better than the hitherto known precision from surveying.