GLONASS

The Global Navigation Satellite System (), usually referred to by the acronym GLONASS (, ), is a Russian satellite navigation system operating as part of a radionavigation-satellite service. It provides an alternative to the Global Positioning System (GPS) and was the second navigational system in operation with global coverage and of comparable precision.

PZ-90 (short for Parametry Zemli 1990 goda, in ) is a geodetic datum defined for use in the GLONASS system.