Progress towards joint civil use of GPS and GLONASS

Navstar GPS (Global Positioning System) and GLONASS are approaching the onset of their operational phases, probably reaching full global, continuous 3D coverage during the period 1994-95. GPS and GLONASS are intended to operate as stand-alone systems, but much discussion has revolved around the question of the joint use of GPS and GLONASS for civil applications, perhaps augmented by a small number of geostationary satellites to be provided by Inmarsat. Of particular interest in this regard are the plans of the civil aviation community to use global navigation satellite systems as a supplementary and later as a sole-means navigation system.<>