Druzhin Andrey

Andrey V. Druzhin is a senior scientific researcher at the Synchronization Systems Department of Russian Institute of Radionavigation and Time, St. Petersburg. Graduated from Herzen State Pedagogical University of Russia, St. Petersburg in 1996 and received a Doctor of Philosophy degree in theoretical physics in 2001.


«Possible Transfer to the UTC Continuous Scale – Consequences for GLONASS»
Coordinated Universal Time UTC was defined and adopted as a continuous time scale implemented by atomic reference clocks and adjusted for “leap” seconds to maintain the agreement with the mean solar time of the prime meridian corrected for polar variation UT1 better than 1 s, according to astronomical observations.
In 2002 International Telecommunication union (ITU) adopted Recommendation ITU-R TF.460-6 “Standard-frequency and time-signal emissions” which regulates conformity of all standard-frequency and time-signal emissions, produced by radiocommunication and navigation systems, to UTC adjusted to UT1 by the insertion or deletions of “leap” seconds.
However, since 2008 there has been much discussion at ITU on the revision of Recommendation ITU-R TF.460-6 and redefinition of UTC. This redefinition implies transformation of UTC implementation, i.e. elimination of insertion or deletions of “leap” seconds and, as a result, accumulating the difference between UT1 and UTC.
Now GLONASS Time is synchronized to UTC(SU) which is Russian national realization of UTC, and is corrected by “leap” seconds together with UTC corrections.
The paper presents the possible consequences of UTC redefinition for GLONASS. The most crucial of them are:
  • modification of software for GLONASS space vehicles;
  • modification of GLONASS Ground Segment;
  • modification and/or replacement of user equipment as the existing one won’t be able to provide navigation solution.