A two-level approach to VLBI terrestrial and celestial reference frames using both least-squares adjustment and Kalman filter algorithms

Benedikt Soja1, Hana Krasna2, Johannes Boehm2, Richard S Gross1, Claudio Abbondanza1, Toshio Michael Chin1, Michael B Heflin1, Jay W Parker1 and Xiaoping Wu1, (1)Jet Propulsion Laboratory, California Institute of Technology, Pasadena, United States, (2)Technische Universität Wien, Department of Geodesy and Geoinformation, Vienna, Austria