Determination of the position of Jupiter from radio metric tracking of Voyager 1

The Voyager 1 spacecraft flew by Jupiter on March 5, 1979. Spacecraft navigation was performed with radio tracking data from NASA's Deep Space Network. In the years since then, there has been a great deal of progress in the definition of celestial reference frames and in determining the orbit and orientation of the Earth. Using these improvements, the radio metric range and Doppler data acquired from the Voyager 1 spacecraft near its encounter with Jupiter have been reanalyzed to determine the plane-of-sky position of Jupiter with much greater accuracy than was possible at the time of the encounter. The position of Jupiter at the time of encounter has been determined with an accuracy of 40 nrad in right ascension and 140 nrad in declination with respect to the celestial reference frame defined by the International Earth Rotation Service. This position estimate has been done to improve the ephemeris of Jupiter prior to the upcoming encounter of the Galileo spacecraft with Jupiter.