Definition study of land/sea civil user navigational location monitoring systems for NAVSTAR GPS: User requirements and systems concepts

A low-cost GPS civil-user mobile terminal whose purchase cost is substantially an order of magnitude less than estimates for the military counterpart is considered with focus on ground station requirements for position monitoring of civil users requiring this capability and the civil user navigation and location-monitoring requirements. Existing survey literature was examined to ascertain the potential users of a low-cost NAVSTAR receiver and to estimate their number, function, and accuracy requirements. System concepts are defined for low cost user equipments for in-situ navigation and the retransmission of low data rate positioning data via a geostationary satellite to a central computing facility.