ABSTRACTDespite the global coverage and high accuracy achievable through GPS and GLONASS, a number of organizations in Europe see a need for alternative satellite‐based navaids. NAVSAT, GRANAS, Rexstar, Locstar, and INMARSAT'S proposed enhancements of GPS/SPS all use existing geostationary communications satellites. NAVSAT adds satellites in highly inclined orbits to those in geostationary orbit to achieve global coverage. Institutional and straight commercial issues assume considerably more importance in civil than in military system