An exact distance between both can be found by a Very Long Baseline Interferometry (VLBI) that observes simultaneously the electric wave which arrives from a heavenly body and another antenna.
These telescopes observe the exact position of the satellite which passes through the sky in order to search for the more highly precise orbit of satellite.
The communication experiment with a geostationary satellite was conducted. Among two big antennas, the right was used for CS (communications satellite), and the left was used for the experiment of BS (broadcasting satellite).
As Japan’s sole independent administrative institution specializing in the field of information and communications technology, the National Institute of Information and Communications Technology (NICT) is charged with promoting ICT sector as well as research and development in ICT, which drives economic growth and creates an affluent, safe and secure society.
Introduction video (13 minutes)