PZ-90 geodetic system
A consistent set of parameters used in GLONASS describing the size and shape of the Earth, positions of a network of points with respect to the centre of mass of the Earth, transformations from major geodetic datums and the potential of the Earth, developed in 1990.
Source: Nick Ward, Vicechair, IALA e-Nav Committee, March 2009
Global Navigation Satellite System, operated by the Government of the Russian Federation
Globalnaya Navigatsionnaya Sputnikovaya Sistema
International Association of Marine Aids to Navigation and Lighthouse Authorities - AISM