Automated geodetic Very Long Baseline Interferometry observation and data analysis system

A precise geodetic measurement network using three modern space geodetic techniques, i.e. Very Long Baseline Interferometry, Satellite Laser Ranging, and Global Positioning System, is being established around Tokyo, Japan by the Communications Research Laboratory. The Key Stone Project, which is the name of the project, was started to obtain precise relative positions of four stations using these three space geodetic techniques on a daily basis. The system was designed to make frequent observations possible with minimum human operations and to provide analyzed results as fast as possible. This paper describes various aspects of new features and the performance of the automatic geodetic Very Long Baseline Interferometry observation and data analysis system designed for the Key Stone Project. This automated design has allowed daily Very Long Baseline Interferometry experiments to be conducted since January 1995 and the results to be immediately made available for public use after each experiment.