Recommendation 1 of the 85th CIPM (1996)

Coordination of satellite systems providing timing

The Comité International des Poids et Mesures,


  • the international value of having both Global Positioning System (GPS) and Global Navigation Satellite System (GLONASS) operational with a composite contribution of 48 satellites,
  • the desirability of using either or both systems interchangeably,
  • that currently significant time differences exist between the two systems,
  • that significant differences exist in the coordinate reference frames used for each,
  • that other important satellite timing systems are now being designed and developed,


  • that the reference times (modulo 1 second) of satellite navigation systems with global coverage* be synchronized as closely as possible to UTC,
  • that the reference frames for these systems be transformed to be in conformity with the terrestrial reference frame maintained by the International Earth Rotation Service (ITRF),
  • that both GPS and GLONASS receivers be used at timing centres.

* Such as Global Positioning System (GPS). Global Navigation Satellite System (GLONASS), International Maritime Satellite Organization (INMARSAT), Global Navigation Satellite System 1 (GNSSI), Global Navigation Satellite System 2 (GNSS2).

DOI : 10.59161/CIPM1996REC1E

The reader should note that the official version of this Resolution is the French text

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