The Global Navigation Satellite System (GLONASS) is a space-based radionavigation system being developed by the Russian Federation. Having much in common with the United States' Global Positioning System (GPS), GLONASS can provide accurate estimates of position, velocity, and time to users worldwide. Both systems were planned in the 1970s primarily for military use, and are operated by the respective defense departments. Each country has committed to make a subset of the signals available for civil use without any user fees. Detailed descriptions of these signals have been made available for each system so that receiver manufacturers can build and sell user equipment.