  The space probe 'New Horizon' was launched on 19th of January 2006 in order
to study Pluto and its moons. Spacecraft will fly by Pluto as close as 12500 km
in the middle of July 2015 and will get the most detailed images of Pluto and
its moon until this moment. At the same time, observation obtained by the
ground-based telescopes may also be helpful for the research of such distant
system. Thereby, the Laboratory of observational astrometry of Pulkovo
Observatory of RAS made a decision to reprocess observations obtained during
last decade. More than 350 positional observations of Pluto - Charon system
were carried out with the mirror astrograph ZA-320M at Pulkovo and Maksutov
telescope MTM-500M near Kislovodsk. These observations were processed by means
of software system APEX-II developed in Pulkovo observatory and numerical
simulation was performed to calculate the differences between positions of
photocenter and barycenter of Pluto - Charon system.
